LONDON, Oct 9 (Reuters) The richest man in Britain's history is not a steel magnate, trader or football club owner, but a soldier.
Alan Rufus, a French immigrant, who came over to Britain to help his uncle William the Conqueror in 1066, amassed a fortune worth an estimated 81.3 billion pounds in today's money.
It dwarfs Chelsea football club owner Roman Abramovich's 10.8 billion pounds, and steel tycoon Lakshmi Mittal's 19.3 billion and is nearly three times the wealth of Microsoft co-founder Bill Gates.
Old money dominates a list of Britain's wealthiest over the centuries, with landowners, traders, bankers, the clergy and the military dominating the top 250 places.
Mittal comes in at 20, while Abramovich is at 59.
The list is published in a book called ''The Richest of the Rich'' by Philip Beresford, compiler of the annual Rich List for the Sunday Times, and William Rubinstein, professor of history at the University of Wales, Aberystwyth.
Published by Harriman House, it excludes monarchs, whose wealth is difficult to calculate.
When Rufus died at 53 he had a fortune of 11,000 pounds, thanks largely to the huge swathes of land he was given by William for suppressing Saxon rebellions in the north.
Beresford and Rubinstein, using figures from probate records and ancient documents, calculated that the sum represented more than 7 per cent of the net national income of the time. With an equivalent percentage today, he would be worth 81.3 billion pounds.
Rubinstein told Reuters: ''The further back you go, the wealthier the wealthy were. It was easier to become wealthy in the past than it is now.
''Plainly the wealth was based on land and trading before the industrial revolution. Since then much more of the rich have come from the City of London.
''The biggest surprise was how much the rich were affected by tax and death duties during the mid-20th century. It squeezed the wealth out of them.'' Other figures who feature in the top 20 of the rich list include the soldier and landowner Richard Fitzalan, 10th Earl of Arundel, (1307-1376) who used his 59.4 billion-pound fortune to help bail out the king; Archbishop of Canterbury Thomas Becket (1120-1170) who had an estimated fortune of 24.6 billion pounds and James Craggs (1657-1721) who made 20 billion pounds thanks to his army clothing contracts.
Among living Britons are the 6th Duke of Westminster, who owns hundreds of acres of the most exclusive commercial and residential property in central London, comes in at 102 with 7 billion pounds and retailer Sir Philip Green, who is at 140 with 4.9 billion pounds, Reuters SG DB2027