(Photo: AP Photo/Museum of London Docklands)

LONDON (AP) — A new database launched Wednesday lets Britons uncover uncomfortable information — whether their ancestors owned slaves.

Researchers at University College London spent three years compiling a searchable listing of thousands of people who received compensation for loss of their "possessions" when slave ownership was outlawed by Britain in 1833.

Some 46,000 people were paid a total of 20 million pounds — the equivalent of 40 percent of all annual government spending at the time — after the freeing of slaves in British colonies in the Caribbean, Mauritius and southern Africa.

Their descendants include writers Graham Greene and George Orwell. Orwell's real name was Eric Blair, and the trustees of his great-grandfather, Charles Blair, were paid 4,442 pounds for 218 slaves on a plantation in Jamaica.

Research associate Keith McClelland said the project would help show how the legacy of slavery still affects Britain.

He says 10 percent of wealthy 19th-century Britons were directly connected to the slave trade, and proceeds helped build railways, businesses, buildings and art collections that still exist today.

"You are talking about a very important component of the British economy from the 17th century onwards," McClelland said.

Britain's Parliament abolished the slave trade in 1807, but slavery itself was not outlawed in its colonies until 26 years later. The United States followed in 1865 and Brazil in 1888.

In 2006 then-Prime Minister Tony Blair expressed "deep sorrow" for Britain's role in the trans-Atlantic slave trade, though some felt that fell short of a full apology. The next year he said: "I have said we're sorry and I say it again now."

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