LONDON – A new database launched Wednesday lets Britons curious about their family history uncover some potentially 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.

About 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.