In the endless catalogue of British imperial atrocities, the unprovoked invasion of Tibet in 1903 was a minor but fairly typical episode. Tibetans, explained the expeditions cultural expert, were savages, more like hideous gnomes than human beings. Thousands of them were massacred defending their homeland, knocked over like skittles by the invaders state-of-the-art machine guns. I got so sick of the slaughter that I ceased fire, wrote a British lieutenant, though the Generals order was to make as big a bag as possible. As big a bag as possible killing inferior people was a kind of blood sport.

And then the looting started. More than 400 mule-loads of precious manuscripts, jewels, religious treasures and artworks were plundered from Tibetan monasteries to enrich the British Museum and the Bodleian Library. Countless others were stolen by marauding troops. Sitting at home watching the BBC antiques show Flog It one quiet afternoon in the early 21st century, Sathnam Sanghera saw the delighted descendant of one of those soldiers make another killing 140,000 for selling off the artefacts his grandfather had come across in the Himalayas.

Its a characteristically instructive vignette in Empireland, Sangheras impassioned and deeply personal journey through Britains imperial past and present. The empire, he argues, still shapes British society its delusions of exceptionalism, its immense private and public wealth, the fabric of its cities, the dominance of the City of London, even the entitled and drunken behaviour of British expats and holidaymakers abroad. Yet the British choose not to see this: wilful amnesia about the darker sides of imperialism may be its most pernicious legacy.

Among other things, it allows the British to deny their modern, multicultural identity. Moving effortlessly back and forth between history and journalism, Sanghera connects the racial violence and discrimination of his childhood in 1970s and 80s Wolverhampton with the attitudes and methods previously used to impose empire and white supremacy across the world and still perpetuated in British fantasies of global leadership.

Along the way, he tackles the racist myopia that allows present-day Britons to fantasise that black and brown people are aliens who arrived without permission, and with no link to Britain, to abuse British hospitality. On the contrary, imperial citizens have been enriching British life for centuries. The pioneering author and entrepreneur, Sake Dean Mahomed (1759-1851), invented the curry house. William Cuffay, the child of a freed West Indian slave and a white woman, helped lead Londons Chartist movement for greater democracy then, after being transported, became a political organiser in Australia.

Millions of others fought for Britain in the second world war alone, 200,000 Indian soldiers were killed, wounded, or captured while serving in allied campaigns. More than 10% of the UKs current population (including a staggering 44% of the NHSs medical staff) is non-white. All this is because for centuries white Britons colonised nations all over the world proclaiming their intimate, familial allegiance while invading, occupying, plundering, humiliating and killing their peoples on a massive scale to benefit British wealth and self-esteem. We are here because you were there.

Without getting bogged down in definitions, calculations or complicated comparisons, Empireland also manages to convey something of the sheer variety of imperial experiences over four centuries, and the limits of broad-brush explanations. Most of Britains wealth probably came from non-imperial trade. Imperial control was made possible by the collaboration of indigenous rulers and groups. Other nations have similarly problematic histories. And theres a long history of Britons themselves criticising, not celebrating, the full, gut-wrenching horror of imperial violence and racism.

But to make too much of such qualifications would be to miss the essential point. Both deliberately and unconsciously, the empire was one of the biggest white supremacist enterprises in the history of humanity, and it still corrupts British society in countless ways. Sangheras unflinching attempt to understand this process, and to counter the cognitive dissonance and denial of Britains modern imperial amnesia, makes for a moving and stimulating book that deserves to be widely read.

So does Padraic Scanlans engrossing and powerful Slave Empire: How Slavery Built Modern Britain, a detailed exposition of how Britain profited from slavery for 200 years, and then used its abolition to justify another century or more of imperial violence and capitalist exploitation.

Its a different kind of book: straight history, no memoir, a scholarly rather than a journalistic argument. Yet its propelled by a similar, urgent frustration with the amnesiac myths of Britains supposedly glorious imperial heritage.

In the popular imagination, Britains abolition of the slave trade in 1807, and of slavery itself after 1833, was a great victory of good over evil, a national sacrifice that wiped out the stain of its slaveholding past. By voluntarily casting off the sin of slavery, the empire was transformed into a beacon of righteousness, and flourished thereafter as a global leader of antislavery and free trade, not bondage.

In the age of Brexit, thats the proud, inspiring history that many Britons love to rehearse. As Scanlan shows, its not a recent invention: its rooted in the vision of the antislavery movement itself. But its deeply misleading. Inspired by the classic West Indian critiques of CLR James and Eric Williams, and synthesising a mass of recent scholarship, Slave Empire presents a series of much more uncomfortable truths.

For one thing, the mass enslavement and exploitation of Africans by Europeans was never incidental or separable from the rise of global trade and empire: it was one of the central mechanisms through which these things were achieved. Slavery itself was an ancient practice. But there had never been anything like the vast slave plantations created in the Americas, especially on the islands of the Caribbean. By the late 18th century, these enormous, brutal, ecologically destructive enterprises had become the hub of a huge, profitable, interdependent web of money, commerce, power and territory, stretching both eastwards across the Atlantic, to Europe and West Africa, and north and south, into the mainland colonies of America.

From the forced labour of the millions of enslaved people who were worked to death on such factory-farms, white Britons and other Europeans created not just a booming international market in sugar, tobacco and rice, but a heavily capitalised imperial economy of shipping, banking, insurance, manufacturing, commodity trading and military expenditure. Even the fine white sugar that Jamaican planters themselves consumed was the product of raw materials grown and processed in the Caribbean, shipped to London, refined by sugar bakers in England, and then transported all the way back across the ocean to be retailed in the West Indies.

Nor did slavery die just because enlightened Britons turned against it. The abolitionist vision was deeply hierarchical, racist and paternalist freedom was something to be gradually earned by blacks and benevolently bestowed by whites. Enslaved people themselves had very different ideas. Long before white Britons took up their cause, they fought fiercely and unremittingly against their bondage.

All over the West Indies, throughout the later 17th and 18th centuries, large numbers of escaped and rebelling slaves waged continual guerrilla warfare on white settlers. In the early 19th century, three major insurrections in Barbados in 1816, British Guyana in 1823, and Jamaica in 1831-32 helped force the hands of the British. Abolition was partly an attempt to prevent black people from emancipating themselves and capturing valuable British territories by force as the rebel slaves of Frances main colony had done when they established the free republic of Haiti in 1804.

Whats more, ending slavery didnt stop the gigantic system of trade and exploitation it had spawned. On the contrary, it was meant to enhance it. The British government paid out colossal sums to compensate slaveowners but nothing to enslaved people themselves. Instead, the law abolishing slavery forced them to continue to labour for years on their existing plantations, as unpaid apprentices.

Abolitionists presumed that freed slaves would work harder, making plantations more profitable. When the price of Caribbean sugar fell, it was their laziness that was blamed. When they had the temerity to demand better wages, thousands of other dark-skinned workers were shipped in as indentured labourers from China, India, and Africa, to take their place as they were to countless other new British plantations around the world. Free labour and free trade were incompatible with slavery, but not with the continued exploitation and global trafficking of low-paid workers.

As Scanlan points out towards the end of this rich and thought-provoking book, 19th-century British capitalists continued to invest heavily in slaveholding enterprises overseas. They funded and insured many of the banks, railroads, steamships, and plantations of the American south. Britains cotton industry grew into its largest and most valuable industrial sector by processing much of the raw material produced by Americas slaves. At one point, the livelihood of nearly one in five Britons depended on it. In almost every respect, the free trade empire was less a repudiation than a continuation of the empire of slavery. Its time to embrace a more honest understanding of its manifold legacies.

Empireland: How Imperialism Has Shaped Modern Britain by Satnam Sanghera is published by Viking (18.99); Slave Empire: How Slavery Built Modern Britain by Padraic X Scanlan is published by Robinson (25). To order copies go to guardianbookshop.com. Delivery charges may apply.

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Empireland by Sathnam Sanghera and Slave Empire by Padraic X Scanlan review - The Guardian