David Olusoga: More than a quarter of all the nations on Earth are former British colonies, and scattered across the world are the ruins of the British Empire-- statues to kings and viceroys, slave fortresses, plantations, schools, railways, and prisons.

At its height, the British Empire, the biggest there has ever been, ruled over a fifth of the world's land surface and almost a quarter of its people, and perhaps the greatest legacy of the British Empire is a living legacy.

There are today literally billions of people whose ancestors, in different ways, were part of this story.

For this episode, we asked people from across the world to share their views on the contested histories and the modern hybrid identities that were left behind when, after 4 centuries, the British Empire finally came to an end.

Nishant, voice-over: Stories of Empire, we flatten out people within them-- everybody who is British behaved in one way; everybody who was Indian behaved in one way, so whether something is ethical or unethical, how they interacted, what they felt, we lose a lot of that richness, and I think it's a shame.

I don't think that there is only kind of one side to the story of Empire.

You know, not everything was negative.

Histories of Empire really do allow us to understand, you know, why there are so many people from Caribbean, Asia, and everywhere else here now.

Looking back on my life and reflecting on choices that I made, an Indigenous woman in the middle of Britain-- who would have thought?-- talking to you now about the impact that that colonialism has had on my people, that's me.

That's who I am.

I'm an [speaks Omaha-Ponca].

♪ ♪ Olusoga: The history of the British Empire lives on across the world, even here on the Great Plains of Canada, in the vast spaces of the province of Alberta, and the tiny city of Medicine Hat... ♪ and here in the vaults of the local museum is an object so precious to the Indigenous Kainai community that before it can be revealed, it has to be blessed in a traditional ceremony.

The object is something I've known about for years, but what I haven't realized until this moment is just what it means to the Kainai people because to carry out the ceremony that's needed for me, as an outsider, to view it, a teepee has been erected here, and elders from the tribe have gathered to carry out that ceremony because this object is a vital piece of their history, but it's also a piece of history of the British Empire.

The object in question is known as the Great War Deeds of Mike Mountain Horse.

Mike Mountain Horse was a member of the Kainai Blood Tribe, who, as a subject of the British Empire, took the warrior traditions of his people into a war his ancestors could not have imagined-- the First World War.

Man: [Speaking Blackfoot] Olusoga: Each of these panels represents a memory, an event that Mike Mountain Horse lived through on the Western Front.

Man: [Speaking Blackfoot] Olusoga: His War Deeds depict the trenches... shells detonating over the heads of the figures... [Explosions] artillery, explosions, and death.

Man: [Sings in Blackfoot] Olusoga: Over a century after he returned from the trenches, his descendants revere this object.

It is both part of their spiritual world and, as much as any document in any archive, it is a record of history.

Man: [Speaks Blackfoot] Olusoga: What do the War Deeds of Mike Mountain Horse mean to you and your people spiritually?

For him to sign on a dotted line to protect his country in a much bigger stage, he must have had a great understanding of the purpose he had in his life.

Fox: [Speaking Blackfoot] Olusoga: Millions of men got back from the Western Front traumatized.

Is the painting a form of therapy for someone like Mike Mountain Horse?

Oh, definitely.

To be able to share the difficult things that he went through and putting it on that hide is to tell everybody in the world, "This is what happened," you know, so it went from here to there.

But the result is also something which is a piece of history.

That's right.

We didn't write anything down.

A lot of the teachings that we have, because of our oral history, it's really an experiential learning.

Fox: [Speaking Blackfoot] ♪ Olusoga: The homelands of the Kainai people, the landscape Mike Mountain Horse knew, lie 4,500 miles from the battlefields of Europe.

Part of the Canadian Prairies, it is a land of vast plains and deep river valleys, home to the reserves and the settlements on which many Kainai people still live.

This landscape could hardly be more different from the fields of France and Belgium where the Western Front stood, and Mike Mountain Horse found himself on the Western Front because he and his people were subjects of the British Empire, and in the early years of the 20th century, after more than 300 years of Empire building, that meant that he was part of a vast global system that, in all sorts of ways, tied together over 400 million people, almost 1 in 4 of everybody on the planet... ♪ and perhaps nothing gets across the scale and the reach and the diversity of that Empire than the fact that people who lived in places as remote as this could find themselves transported across oceans to fight and to labor in the name of that Empire.

♪ Mike Mountain Horse was one of 4,000 Indigenous Canadians who fought in the name of the British Empire, and they were not alone.

Volunteers from the Caribbean colonies rushed to join the British Army.

Thousands of Africans were recruited to take the war to Germany's African Empire, and from India, over a million men were sent to the Western Front and the Middle East, with many Indians supporting the war in the hope that their loyalty would win them a greater voice in Indian politics.

The First World War ended not only with victory for the forces of Britain and its Empire, but with the last great expansion of that Empire, because it was in the years after the war, in the early 1920s, as Britain took over the colonies of the defeated powers, that the Empire reached its maximum size, and yet at that moment, as the Union Flag was raised over new colonies, the Empire was just one generation away from collapse.

[Birds chirping] ♪ The idea that the Empire was approaching its final decades would have seemed ridiculous to the thousands who gathered here on this ridge to the north of Delhi in the year 1911 because this was the site of perhaps the most flamboyant ceremony in the whole history of the British Empire-- the grand Durbar of King George V. 200 Indian princes, along with the British officials and soldiers who administered the Raj and tens of thousands of guests, gathered here to offer obeisance to the king emperor.

♪ This monument marks the exact spot from which the King surveyed the scene and gave a historic speech.

At the very end of his speech, this British king informed the Indian people that the capital city of their country was to change.

India was no longer to be ruled from Calcutta, the city from which the old East India Company had grown rich and powerful back in the 18th century.

Modern, 20th-century India was to be ruled from Delhi, but this wasn't simply to be a transfer of power from one city to another.

A new city, a new Delhi, was to be created.

♪ The Durbar of 1911 was part of a strategy that had been developed in the decades since the so-called Indian Mutiny.

The British aimed to inspire loyalty among their Indian subjects by using spectacle and by co-opting Indian traditions... ♪ but the Durbar and the decision to move the capital also reflected a new imperial reality.

Historian Swapna Liddle has written about New Delhi and about why it was built.

What does it say about British power in India, this decision to create this new capital?

The kind of state that the British Empire was was one that sought, at least, a semblance of legitimacy in the eyes of the Indian people and, when we come to the beginning of the 20th century, was fighting this difficult battle with Indians who were demanding more and more and being denied again and again.

Because this is the age of the rise of Indian nationalism.

Of Indian nationalism, so there's a rethinking of the image of Empire, and the idea was that we have to give in to some of the, shall we say, "reasonable" demands, but how do you make the British Raj more acceptable in Indian eyes?

And the idea is Delhi in order to reduce British Indian government's role to that of an imperial power, giving more autonomy to provinces, so it's a devolution.

But under British control.

Yes, and this is what brings us to why Delhi, because then you are remaking the British Raj in the image of, shall we say, other Indian empires.

It was the capital of the Mughals.

It was the capital of earlier sultanates before that, so it has that aura of power.

The architects are given this very clear brief that, "You must draw on this legacy "of imperial, monumental architecture around you in order to design this city," so the planning of the city, for instance, this Central Vista, which came to be called Kingsway, is exactly parallel to Chandni Chauk, the main ceremonial avenue of the Mughal city, and the use of red sandstone, this is the material of which a lot of the monumental imperial architecture in Delhi of earlier eras is also built, so you have the Red Fort, for instance.

It's not easy to transport all of this here, but they think it worth their while to do this.

The appeal of Delhi was that it had all of these associations with past great Indian empires, but all of those empires had fallen, so, in a way, there were those at the time who thought this was kind of a bad omen to move to Delhi, to be surrounded by the ruins of earlier empires.

It's interesting that all the objections to this program actually come from prominent, conservative British voices.

There are very few Indians who are against this.

In fact, they are all for it.

The Indians recognize it for the concession it is to Indian demands.

Their strategy is, "Let's go to the next step.

Now let's ask for more."

So the symbolism, the taking of these motifs and designs from Mughal history, that's appreciated, but it's not enough.

It's one step in a series of demands.

Absolutely.

The British seemed surprised by it, but really, they shouldn't have been because--ha ha!-- British responses never kept up with what Indians would demand, and this is an inexorable-- ha ha ha!--march towards independence.

♪ Olusoga: The new capital for the new phase of British imperial rule in India took 20 years to build.

50 miles of roads were cut across a city of parliaments, ministries, homes, and shops that covered 62 square miles.

♪ The final cost was over £10.5 million, almost a billion pounds in today's money.

The official opening of New Delhi took place two decades after the plan to move the capital from Calcutta had first been announced.

The building of this city, the building of all of this, that had been achieved at colossal expense.

This city was regarded as such a priority that work continued even through the darkest years of the First World War, but the year in which that grand inauguration ceremony took place, that was 1931, just 8 years before the outbreak of a Second World War.

♪ When the Empire went to war in 1939, attitudes towards the conflict and towards the Empire were very different to those that had dominated back in 1914, when India's ruling elite had embraced the outbreak of that war as a chance to win concessions.

In 1939, the coming of war intensified the growing campaign for an end to British rule, a reality that was concealed behind the wartime propaganda.

This poster was produced in 1941 by the Ministry of Information, Britain's wartime propaganda ministry, and it projects the image that the government wanted to project.

Under a fluttering Union flag are men representing the armed forces of Britain.

In the front row is a British sailor, an Australian soldier, and a Canadian airman.

Behind them are soldiers from Britain and New Zealand.

At the back is an Indian soldier, and the positioning of these men reflects the racial hierarchies of the British Empire because India's contribution, in terms of soldiers, was by far the greatest of any of the colonies.

By 1945, the Indian Army was 2.5 million strong.

Only at the very back, up in the corner, do we have a depiction of an African soldier, but looking at this poster here in India underneath a memorial to Indian soldiers who died in the First World War, what is most striking is that this image bears almost no relation to reality because the war years here in India were not years of togetherness.

They were years of mass political protest, years of British political oppression, and the years of a catastrophic famine in Bengal in which around 3 million Indians died.

And at the end of the war, after all of that, it was obvious to many people that demands for Indian independence had just grown too strong and that Britain economically, militarily, and politically was just too weak to resist those demands.

♪ In 1946, the British government accepted the inevitable, and the last viceroy, Lord Mountbatten, was dispatched to India.

He was tasked with plotting a path to independence, which by then, it had become clear, meant partition, and, fearful that India could slide into a form of civil war, independence and partition were rushed.

When Independence Day came in 1947, two nations emerged, and two independent ceremonies were held-- one in Lahore in Pakistan, the other in the Parliament of New Delhi, the city from which the British had imagined that they would continue to rule over India.

♪ On the eve of independence, 7 out of every 10 subjects of the British Empire were Indian.

At the stroke of midnight, those 400 million people became citizens of independent India or Pakistan.

For two centuries, India had been an economic and military engine that had kept the whole system of Empire working.

It was in India that the British really learned how to be imperialists.

India's economy had been tethered to the needs of Britain, and the Indian taxpayers had paid not just for their own colonization, but for the development and the defense of other parts of the Empire, and Indians themselves had been shipped right across the British Empire to grow sugar cane in the Caribbean and to build the railways in East Africa.

India's people, India's economy had been key to making the British Empire possible, and then in 1947, with Britain exhausted and virtually bankrupt after 5 years of war, this whole system suddenly came to a violent end.

♪ The legacies of that moment of partition and of the violence that accompanied it are part of the family histories of millions of people.

Natasha, voice-over: It was chaos.

It was absolute chaos.

It was one of the largest mass migrations in human history-- 15 million people displaced, so many deaths.

Man: The judge who was tasked with splitting India and Pakistan was only given 5 weeks.

Woman: Our family would have had land in Sind, and our home was in Jullunder in Punjab in India, and in 1947 when the partition happened, Sind fell into Pakistan, and Jullunder fell into India, and my great-grandparents were in Sind at the time.

♪ What eventually transpired was, my great-grandmother jumped into a well to save herself from either being abducted or raped, and my great-granddad died fighting, trying to protect himself and his family.

They also had their daughter with them, my great-aunt, who also took her own life, and my granddad would have been a 10-year-old waiting in Jullunder for his parents to come home.

♪ ♪ Olusoga: Despite the loss of India, Britain after the Second World War still ruled over tens of millions of people scattered over dozens of colonies and protectorates and in the self-governing dominions like Canada, Australia, and New Zealand.

But in the aftermath of the Second World War, Britain faced a crisis at home.

Shortages of basic foods-- like milk, eggs, and cheese-- were worse after 1945 than they had been during the war years, and rationing continued into the mid-1950s.

The nation that had been the world's banker now had debts of £3.5 billion and was dependent upon loans from the United States.

♪ To generate income to pay off those vast debts and produce food for a British population desperate for better times, politicians turned their attention to the most neglected part of what was left of the Empire-- Africa.

In the late 1940s, thousands of agriculturalists, climatologists, and engineers were sent to Africa to launch an agricultural revolution.

The most grandiose of the investments in Africa was focused on Kenya and Tanganyika, modern Tanzania.

It was a vast scheme to grow groundnuts, peanuts, that could be crushed for cooking oil, one of the everyday essentials in desperately short supply back in Britain.

The whole scheme was built on the belief that modern machinery, heavy tractors and bulldozers, would simply be able to sweep away the vegetation here in East Africa, and then when the land was cleared, crops could be planted and harvested, again, using the latest machinery, but the tractors imported into East Africa from America had been designed for the prairies of the American Midwest.

They weren't strong enough.

They just weren't resilient enough to take on this sort of dense African bushland, and so there weren't enough spare parts.

There wasn't enough space in the workshops to repair machines.

There wasn't even enough diesel, and so, despite all of the ambition and all of the money thrown into it, the groundnut scheme very rapidly began to fall behind schedule and go over budget.

♪ The generation of experts and civil servants who were sent to Africa were almost all veterans of the Second World War, and they were proud of Britain's wartime tradition of overcoming obstacles by improvising, and so when it became clear that the machines brought to Africa were not up to the task, they again improvised.

580 Sherman tanks left over from the war were purchased, and the engineers at the Vickers factory in Newcastle removed the guns and the armor and converted Sherman tanks into heavy bulldozers known as Shervicks, yet even these Shervicks, each of them weighing 18 tons, were not capable of clearing the land at the speed envisaged in the original plans, and across some of the areas identified for groundnut cultivation, the British planners encountered another enemy--the baobab tree.

The teams that were sent out to clear the land for the groundnuts discovered that even converted Second World War tanks couldn't topple baobab trees, and even when baobab trees were cut down, it was almost impossible to remove their huge, bulbous roots from the soil, and there is something ironic about this vast investment in the African Empire being stopped literally in its tracks by these trees because baobabs are not just enormous.

They're also ancient.

These trees can live for over 2,000 years, which means some of the baobabs that stood in the way of the groundnut scheme in the middle years of the 20th century had been standing back in the first years of the 17th century, when the first English ship set sail to establish the first English colonies.

These trees were older than the British Empire.

These ancient trees and this ancient landscape in the end defeated the economic planners of postwar Britain.

In 1951, the government finally canceled the groundnut scheme, an imperial fantasy that had wasted £36 million, a billion pounds in today's money.

Britain's attempt to use its African colonies to solve its domestic problems had been a failure.

♪ Postwar Britain was not just blighted by shortages and burdened with debts.

It was also devastated by years of bombing.

The damage was so extensive that it was visible from the air.

Just after the war, the aerial reconnaissance planes of the Royal Air Force that had been used to find targets in Germany during the war were deployed for a very different purpose.

♪ What the RAF produced was a huge aerial survey of the nation, a photographic Domesday Book of Britain after 6 years of war.

These are the docks of Liverpool.

This is what is left of the center of Bristol.

And this is the devastation around St. Paul's Cathedral.

The scale of the damage was enormous.

The whole nation was in desperate need of reconstruction and modernization.

♪ To rebuild the country, it was estimated that 1.3 million additional workers were needed, and one way the government set about finding them was by encouraging immigration.

Between the late forties and the 1960s, hundreds of thousands came from Ireland, thousands more from the displaced persons camps of Eastern Europe, and this place, Tilbury Docks, is famous today as the port into which one ship arrived--the Windrush, carrying hundreds of workers who had come to Britain from the Caribbean, Britain's oldest colonies.

♪ The passenger list of the Empire Windrush that arrived here at Tilbury on the 21st of June 1948 has become a rather famous document in British history, and if we look in this column that describes the profession, occupation, or calling of the passengers, we can see that many of the people coming to Britain on the Windrush to begin new lives have exactly the skills that postwar Britain desperately needed.

So there's a gentleman here from British Guyana who is an engineer.

On the following page, there's a long list of people arriving from Bermuda, and among them is a boilermaker.

Here is an electrician.

And there is, of course, a story to be told about these people, about their contribution, about the obstacles and the racism that they faced in postwar Britain, but there's another story about movement and about migration around the British Empire that we talk about a bit less, and that story can also be told through the stories of the ships that come here to Tilbury docks and the passengers who came through these arrival halls.

This is another passenger list for another ship--the Maloja, and that was here at Tilbury on the 10th of June 1948, so 11 days before the Windrush arrived, and this, again, is a long list of passengers, but these people are not coming to Britain to start new lives.

These people are emigrants.

These are people leaving Britain, and they're headed to what this form describes as their country of intended future permanent residence, which, in the case of all of these people, is either Australia or it's New Zealand, and let's look at that same column-- profession, occupation, or calling of the passengers-- and here we have a truck driver, a factory worker, a laborer.

There's a woman here called Margaret Black.

She's heading off for a new life in Australia, and under profession or occupation, she's listed as a hospital worker, and the timing here is what is critical.

The Maloja leaves Tilbury Docks exactly 25 days before the new National Health Service opens its doors for the first time, and the first crisis faced by the NHS is a lack of hospital workers and nurses, and there are thousands of other nurses, thousands of other people with critical skills who leave on thousands of other ships in the years after 1945.

♪ Ever since the 17th century, the colonies had been places to which British people had traveled in the hope of transforming their fortunes, but the last great wave of imperial emigration was unlike all those that had preceded it.

Emigration had always been part of the story of the British Empire, but the emigration that takes place after the Second World War takes place in a very different context.

Absolutely.

In the 1920s, the British wanted to get people to emigrate to the Empire.

There was high unemployment, and there was a worry about overpopulation.

After the Second World War, the story is radically different.

There's a shortage of labor and actually a worry about population decrease.

Nevertheless, emigration is back on the agenda.

People want to go, and the government wants to encourage people to go to the so-called white dominions.

So this is Australia, New Zealand, Canada...

Exactly.

the old settler colonies.

The old settler colonies, which were sometimes called the British Commonwealth of Nations, including the United Kingdom itself.

And yet even though they are desperately in need of every laborer, every worker, every skilled worker that they can keep, British governments not just encourage, they even subsidize emigration.

They subsidize emigration.

They want to maintain the British Empire as a world power, and it's been pulled apart as a world power because the United States is so strong, so Canada is getting closer to the United States.

So are Australia and New Zealand, so the British government wants to send more British people-- "British stock" is the phrase-- to populate these places so that they remain, in some sense, within the British orbit.

They're worried that if, as actually happens, the Australians bring in displaced persons from Greece and from Italy, that Britishness will be diluted.

So we have an extraordinary situation where the United Kingdom is exporting people.

I mean, over a million people go in the late forties and 1950s.

In a country of less than 50 million... Yep.

that's a very considerable number of people.

It is.

Immigration into the UK is much lower than, than emigration, so the idea that we have that postwar Britain is a country of immigration from former Empire is actually misleading because the great movement is outwards.

Because it's small numbers, particularly in the forties.

It's small numbers.

It's very small numbers.

We're very aware that immigration from the Caribbean and from India is going to change Britain, but it's far more people come from Ireland.

Far more people come from Ireland and more people from continental Europe, actually, than from the Caribbean or from India, and it's also important to note that the British government-- like Australian government, the Canadian government-- want to keep the country white.

Immigration from the Caribbean and India is absolutely not encouraged.

They only want "Europeans" or "British stock" to come to the country, so it's a profoundly racist understanding that's at work here.

And this is one of the big stories of the British Empire and one of the most forgotten stories, that it was an empire of emigration.

It's one of these remarkable cases where really, really important facets of our history are not common knowledge.

Olusoga: By 1952, around half a million people had left Britain for the Commonwealth, but that year came to be remembered as the start of a new age, one that began not in Britain, but in one of Britain's African colonies.

This is Treetops, a safari lodge in Kenya.

On the 6th of February 1952, the then-Princess Elizabeth was here when her father George VI died and she became Queen.

♪ Here in Kenya, Princess Elizabeth became Queen not just of the United Kingdom, but of what in the early fifties, even after Indian independence, remained an enormous empire, and so at the beginning of the second Elizabethan age, there was still the view within Britain's governing classes that--despite the setbacks, despite the country's precarious finances-- that the Commonwealth could still guarantee a degree of global influence and that there were parts of the Empire, certain colonies, in which British rule could continue in some form for decades, perhaps even for another generation... ♪ but the second Elizabethan age was not to be a new chapter in the history of the British Empire, but an age of decolonization.

In Africa and the Caribbean, demands for independence became irresistible, and in 1956, after independent Egypt nationalized the Suez Canal, the limits of British power were exposed when the United States forced Britain and her allies to withdraw after an invasion.

With Britain's position in the world fatally undermined, the late fifties and the 1960s saw members of the British royal family become participants in a familiar ritual.

♪ At stadiums and racecourses across the world, crowds were gathered, political leaders assembled.

The Union flag was lowered, and the new flags of new, independent nations raised.

The apparent ease with which the British negotiated the peaceful surrender of the Empire they had spent centuries building was presented as one of the Empire's last great achievements.

♪ The transition from Empire to Commonwealth was portrayed almost as a miracle... ♪ and while there were many colonies in which British rule was peacefully dismantled, this was often not the case where white settlers had arrived in large numbers and taken control of the land, which was exactly the state of affairs in the colony in which the second Elizabethan age had begun.

Over there is the Treetops Hotel that tourists from Britain have been visiting for decades to see the place where Princess Elizabeth became Queen Elizabeth, but that--that is not the original building.

The original Treetops stood about here, where I am now, and the reason that it's not here now is because it was destroyed.

It was burnt down just two years after the Queen had visited.

It was a victim in a rebellion that broke out within months of the Queen's visit.

♪ The fertile highlands of Kenya had been identified as being suitable for white settlement back in the last years of the 19th century, and after both World Wars, British veterans had been encouraged to settle here.

By the 1950s, around 30,000 white farmers owned 12,000 square miles of the best land in Kenya.

The Kikuyu, a people of over a million, owned just 2,000 square miles.

Among the land taken from the Kikuyu was the land upon which the Treetops Lodge had been built.

In 1952, when Queen Elizabeth was at Treetops, a movement was gaining support among the Kikuyu that aimed to recover their land and end British rule in Kenya.

That movement was called the Land and Freedom Army.

It was also known as Mau Mau.

Although the vast majority of the people killed in the Mau Mau conflict were Africans, the killings of white settlers shocked the British authorities into action.

Their response was a huge military deployment.

Thousands of soldiers were sent to Kenya from Britain and from other African colonies, and the bombers of the RAF were used to bomb Mau Mau positions in the forests.

But the British also set up camps in which hundreds of thousands of Kenyans were imprisoned, processed, and interrogated.

Today in the 21st century, memories of what happened in those camps have returned to haunt both Kenya and Britain.

♪ In the countryside 50 miles to the north of Nairobi lies Mweru High School for Boys... ♪ but these buildings have been repurposed because Mweru was not designed or built to be a school.

These buildings were built back in the 1950s, and in recent years, Kenyan historians have gone back to the archives, back to old maps and official British documents to recover the story of what happened here and in places like it.

Anthony Maina is one of those Kenyan historians, and his work has helped uncover what happened when Mweru was an internment camp and British colonial forces were based here.

Maina: This building was a barracks maintained with a hot shower, electricity, and all that, So soldiers, this is where they live.

Yes.

There's a swimming pool nearby.

There's a swimming pool?

Yeah.

In every camp, there was a swimming pool for the British officers.

They used to also have a hangman.

Was there a gallows in this camp?

Yes.

People were being hanged during the night so it was not shown in the public.

So the hangman would get up in the middle of the night...

Yes.

and people would be hanged.

People who have been convicted of crime would be hanged and then buried in unmarked graves.

There must be graves just within the compound.

Because so many people died here.

Yeah.

And are the children at this school taught what happened here?

They know.

In fact, they know.

Those soldiers and that hangman may have been the people who killed their ancestors.

Yes, but I think those people who were Mau Mau were very much traumatized.

They don't speak so much about what happened.

So you have this age where people don't want to talk about places like this.

Exactly.

Olusoga: At no other time in the history of the Empire did the British authorities use the death penalty as regularly as they did in Kenya in the middle years of the 20th century.

1,090 Kenyans were hanged during the Mau Mau Emergency, but Mweru School contains relics of other horrors.

Maina: This room is a torture room, both physical and mental.

A person was put here, removed from other detainees.

And put into solitary confinement.

Exactly.

For you to confess, water was poured.

The prison guards would fill the floor with water.

Yeah, and you have nowhere to sleep, so you have to leave this place.

You have to leave the place being maimed, almost crippled.

I can assure you, many of the detainees were castrated in this room, castration.

In this room?

Yeah.

I've met the [indistinct].

In fact, I have encountered about 3 of them.

How was that done?

Pliers.

With pliers.

Yes.

Oh, my God.

This how.

Those who could not survive died, and their next of kin could not be informed because it was something the colonial government were to hide about.

In fact, I was told that there were more than 20 such cells within Mweru.

♪ Olusoga: I've been to the sites of former detention camps and former concentration camps all over the world, but I've never been to somewhere like this, a former camp in which people were abused and tortured that isn't a museum or a heritage site, but that is a working school, and that decision to reclaim this history and to repurpose this site is one that's been taken very purposefully and very deliberately by many people in Kenya who are determined that this terrible chapter in Kenyan history not be forgotten.

♪ Back in the 1950s, when news broke of what was happening in places like this, there was an outcry in Britain.

It was the killing of 11 Mau Mau detainees in another camp, a place called Hola, that led to the shutting down of the camps.

By 1960, the Mau Mau rebellion had been defeated, and yet to keep control, the British had been forced to make huge political concessions, concessions that led in 1963 to Kenyan independence.

But in the months before the dignitaries and the crowds gathered for the independence ceremony in Nairobi, the British authorities had set out to control how the history of the British Empire in Kenya would be remembered, and in the last weeks of 1963, planes left Nairobi carrying crates of documents, just as documents had been removed in the final days of British rule in other colonies.

Historian Riley Linebaugh has studied what happened in the archives of Britain's last colonies in the last years of Empire.

This document is from 1961, and it's to be distributed, it says, among government officials in Nairobi in Kenya, and it is very strikingly marked with a big letter W. What does that mean?

The W stands for watch.

It's a part of a new record-keeping system that this memorandum is describing.

1961, Kenya's constitutional independence is being negotiated.

We're about two years away from independence itself.

Two years away from independence.

What the W here indicates is, for any person handling this document, they know this is a secret.

It should not be available for anyone to see unless deemed an authorized officer.

Does it give us the criteria?

It does.

There's 4 criteria-- "A, prejudice the security "of the Commonwealth or of any friendly state; "or, B, embarrass Her Majesty's Government; "or... "C, give a political party in power "an unfair or improper advantage; "or, D, endanger a source of intelligence, "or render any individual vulnerable to victimization."

Now, some of those criteria are entirely reasonable-- intelligence, the safety of people whose names appear in the documents-- but point B about embarrassing the government, that's not about security.

No.

It's not clear what it's about, and so it provides those interpreting this memorandum a wide remit to decide for themselves what would be embarrassing or not.

When a document has been stamped with a W, what becomes of it?

Either it's slated to be removed to London or, as the document itself will tell us, it will be destroyed.

Some of the documents that received the W stamp were burnt or drowned in open water.

This reveals how committed not only the colonial administration in Kenya was, but the Colonial Office in London to keeping secret evidence of the Mau Mau rebellion in Kenya.

So in this case, what they mean by "might embarrass the government," they mean evidence of torture, of murder, of camps in which people were held for years.

Correct.

And all of this is being done in secret.

It says, "Secret," at the top of each page of this document.

It's all being done as a self-conscious act of secrecy.

If we come here to point 15, "Indeed, the very existence of the "WATCH" series... "should never be revealed, and, to the same end, "the name "LEGACY" should not be used in a non-designated context."

That title, Operation Legacy, that's very telling.

Mm.

There's a fear precisely of sort of an African reinterpretation of the history of the British Empire.

How widespread is Operation Legacy?

It's Empirewide, so this is a project of secret-keeping that is not limited to the transition to independence, and, in fact, the project of record removal continued through the mid-1990s.

One legacy of Operation Legacy is that it enabled people, even today, to convince themselves that the British Empire was unique among all empires in which that it didn't have these crimes, these blemishes, these terrible incidents, this racism, all the things that are destroyed in the documents that are spirited away.

It allows a sort of maintenance of a form of innocence.

A form of innocence, and also, it has allowed a certain mythology and ignorance over the fact and reality of Empire within the UK itself.

♪ Olusoga: The destruction of documents in Operation Legacy allowed certain parts of the history of Empire to be forgotten, but that is not unique.

♪ After slavery was abolished, that history was slowly airbrushed out of the story of Empire.

The slave fortresses on the African coast were abandoned to the forests, the burial grounds on the plantations forgotten.

The Australian families descended from convicts concealed their family histories, and some of the dynasties grown rich from wealth acquired through the East India Company or in the West Indies brushed those family stories under the carpet.

♪ One of the reasons this history is today re-emerging is because of another story fundamental to the British Empire-- immigration.

♪ After the Second World War, just as the Empire itself was falling apart, the peoples of the Empire, despite official disencouragement, began to settle in Britain in large numbers and become part of British society.

Man: I think as I've gotten older, I've begun to see that Britishness takes influence from so many parts of the world, and so many different communities have come to the UK and have brought bits of their culture, bits of vibrance to this country.

Laurence: People are kind of fed up of the story of Empire being a monologue told mainly by people who look and sound like me, frankly.

There is a crisis in identity in Britain, and I think partly that is because we have not had a grownup conversation about our history.

Olusoga: Immigration from the former Empire has created new hybrid forms of British identity which, in turn, have led to calls for a new, more inclusive version of British history.

Woman: The fact that I've grown up here has meant that I do have this hybrid identity, and, therefore, I'm not, you know, afraid to talk about Britain in a light that perhaps is not positive all the time.

There's a mistake with patriotism which means that you must always speak about Britain in a positive light, but that's just not the case because we need to look at British history as a whole.

It is the reason why I have so much of the culture that I have today.

It's the reason why I listen to soca music and I eat Caribbean foods, and the mosque that I grew up in is an Indo-Caribbean mosque, and every Saturday, that was my experience.

Olusoga: And yet there is still the view among some that the history of Empire is better off forgotten or that the uncovering of this history is intended to make people feel guilty about events that took place before their birth.

Learning the history hasn't made me hate Britain.

The money that was created through slavery and Empire, that's the money that I benefit from today, and the fact that that money was made from my ancestors-- their, like, dehumanization, exploitation-- that is really complex.

I've been on this journey to just discover my roots through London because the Raj, the East India Company, events in World War I, World War II-- all of that is the reason I'm here in London, and that's my story.

♪ Olusoga: As a historian, my attempts to make sense of my own hybrid identity takes me inevitably to the past and to two sets of documents, both held here at the National Archives.

Together, those documents very personally reveal just how deep the history of Empire runs.

The first set of documents are the official records of a tiny event in the story of the British Empire-- an attack by British forces on a small African city in the year 1892.

This map shows the routes that the British forces took as they marched towards their targets, and each of these symbols of a crossed sword, that is a small battle, an engagement that they had with the local African people, and right at the top of the map is their destination, their target-- the town of Jebu Ode.

Now, that is the modern Nigerian town of Ijebu Ode.

Here is a map of the town with its defensive walls and its defensive ditch.

Also among these documents is this list of the weapons and the ammunition that the British forces took with them on this raid.

There is 7-pounder guns-- that's artillery-- with 100 rounds, and there is a Maxim gun, and in 1892, this is just about the most high-tech weapon on Earth, and we know that these weapons were used with devastating effect because we have this account by one of the British officers.

He says, "[N]early all the principal chiefs "had been killed or wounded, "and that there was not a household in Jebu Ode that did not mourn the loss of at least one of its members."

Now, I've stood here in the archives many times, and I've looked at documents and maps just like these because there are many small wars and punitive raids in the history of the British Empire, but these documents, to me, are a bit different because this town, Ijebu Ode, is where the Nigerian half of my family come from, and when I look at this list of weapons, these were weapons that were used against people that I'm descended from.

Other documents right here in the National Archives that really complicate the picture.

This is the discharge papers of another of my ancestors.

His name was David Ewart, and he was a Scottish soldier in the British Army.

He fought in a regiment called the 78th Regiment of Foot, and that was a regiment that was sent to fight in India.

This letter explains what their task was.

It says that their job was "to defend territory "recently acquired by His Majesty's "and the East India Company's arms in various parts of India."

It was the private East India Company, not the British state, that paid David Ewart his army wages.

And what all of this means is that I'm descended from a British colonial soldier and from Africans who were attacked by British colonial soldiers, and this complexity, this messiness, that is just a feature of the history of Empire, a history that just can't be understood through ideas of pride and shame, of them and us, and it's a history that we share with literally billions of people across the world, and--whether we like it or not, whether we're comfortable with it or not-- this is a history that runs too deep and matters too much for it to be brushed aside or wished away.

♪ Kyle, voice-over: Things are never as black-and-white as we think they are, and history is important, and I think people get really scared or upset that we're trying to take that away.

Natasha, voice-over: When has ever knowing the truth about yourself and confronting your past-- when has that ever been something that isn't beneficial to you?

All we have are links and stories of each other.

I don't think it's possible to think of Empire and beyond that in any other way.

♪