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.

“The further back you go, the wealthier the wealthy were. It was easier to become wealthy in the past than it is now,” Rubinstein told Reuters. “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.”