London, Oct.8 : India's Lakshmi Mittal and Russia's Roman Abramovich will now have to take a backseat in a new list of rich people in Britain, as a little-known French immigrant is said to have been a multi-billionaire more than 900 years ago.

When he died more than 900 years ago, Alan Rufus was worth, in today's terms, 81 billion dollars.

According to The Daily Mail, Alan the Red - so-called because of the colour of his hair - tops a list of the 250 wealthiest people in British history in a book called The Richest Of The Rich.

The list excludes monarchs, but the top ten includes a soldier, a diplomat, a landowner, an admiral and a general.

The super-rich of the 20th century are not represented until number 20, with steel magnate Mittal and his 19 billion dollar fortune.

Rufus, who was William the Conqueror's nephew, is followed at the top by William de Warenne, 1st Earl of Surrey, in second place, ahead of the equally obscure Robert of Mortain-Odo of Bayeux and Henry of Grossmont.

Rufus's fortune included 250,000-acres of land across Yorkshire, Norfolk, Suffolk, Cambridgeshire, Northamptonshire and London, which was given to him by his uncle for his part in suppressing a Saxon rebellion in the North.

He also built Richmond Castle in North Yorkshire for himself. When he died in 1093 at the age of 53, he was worth 11,000 pounds.

Using figures from probate records and ancient documents, authors Philip Beresford and Bill Rubinstein have calculated that this sum was more than seven per cent of the national income of the time.

The equivalent percentage today would leave Rufus with 81.33 billion pounds - three times the worth of Bill Gates, the co-founder of Microsoft, and eight times that of Roman Abramovich, who is 59th on the list.

Among other living Brits, Gerald Grosvenor, the 6th Duke of Westminster, makes the list at number 70, with an estimated fortune of seven billion pounds. His wealth is derived from owning around 300 acres of the most exclusive commercial and residential-property in Central London.

David Morris, author of The Honour Of Richmond, a history of the Richmond Castle estate, said: "The closest person to Rufus today would be the Duke of Westminster with his property empire."

The study stretches back to the Norman conquest of 1066. Four of the list's top six were Norman barons, including Edward, the Black Prince, who was worth the equivalent of almost 35 billion pounds, and Archbishop of Canterbury Thomas a Becket, who amassed more than 24 billion pounds in today's money.

The richest woman in British history is Eleanor of Aquitaine, wife of Henry II, who at number 62 had a fortune worth just less than 10 billion pounds in today's terms.

Rufus died in his bed, but of the 250 on the list, 29 were either executed or met a violent death. (ANI)