Belgravia is the source of much of the duke's wealth
The duke is Britain's richest man with his wealth rising from £4.4bn in 2001 to an estimated £4.7bn.
His vast property holdings include 300 acres of hugely valuable Mayfair and Belgravia in London, as well as estates around Britain.
Despite recent economic fears, the wealth covered by the list has increased.
But while those involved in property and retail have done well, many of those owning tech stocks and dot.com interests have continued to suffer.
Food packaging tycoon Hans Rausing retains his second slot for another year.
Supermarket tycoon Lord Sainsbury moves up a place to third from last year and Grand Prix racing baron Bernie Ecclestone stays in the top 10, while slipping from third to fifth spot.
The list is again dominated by men, but one woman made it into this year's top 10.
Charlene de Carvalho - brewer Freddie Heineken's daughter - inherited a £2.96 billion fortune when he died.
With her husband Michel, she becomes the highest new entry at number four in the 14th annual Rich List.
The chairman of Morrison Supermarkets, Sir Ken Morrison, jumps from 18th place last year to ninth in the 2002 list.
Charity donors
Harry Potter Author JK Rowling (147) with £226m beats Madonna (161), whose wealth lies at £200m.
The Queen, whose fortune was estimated at £275m, is in 125th place.
Former Beatle George Harrison's widow Olivia ranks 230th after inheriting £140m from her husband's estate.
Charity donors feature for the first time in the list this year, with the biggest givers being the Sainsburys.
But the most generous charitable donor was Stagecoach transport boss Brian Souter, whose Souter Foundation gave 41.1% of its asset base to charity.