The archives from the London Historical Records feature details of around 165 million of the British capital's citizens over the centuries, including head of state Oliver Cromwell and poet William Blake.

Around 250,000 records are currently available, with all 77 million uploaded by 2011.

The final collection will include parish and workhouse records, electoral rolls, wills, land tax records and school reports.

Tracing the family history has become an increasingly popular hobby in Britain, thanks to the availability of records online and television programmes showing celebrities discovering the quirks of their ancestry.

Besides Londoners, around 135 million people in countries like the United States, Canada, Australia and South Africa may be able to trace their forefathers.

"We estimate that half of Brits will be able to find an ancestor in this collection," said Josh Hanna, senior vice president of the website Ancestry.co.uk which is hosting the London records.

The collection "pre-dates civil registration and census, and documents the history of a great city and its people, their birth, poverty, fortunes, faith, education, marriage and death," he said.

"No city in modern history other than London can claim to have been the capital of such a far reaching empire, which really is why this collection is of such significance not only to Brits, but also to many others around the world with ancestral ties back to Britain."

English football icon Beckham's three-times-great-grandparents' marriage is listed, while US singer Spears' great-grandfather, George Portell, is listed in the Tottenham district's marriage records for 1923.

(c) 2009 AFP