Lakshmi Mittal, owner of ArcelorMittal, who held the top slot in 2008 with £27.7bn now has a fortune of £7.12bn and is number 11 on this year's list.
The number of London billionaires fell for the first time since the financial crash - from 80 in 2015 to 77.
There are also a record 125 women on this year's top 1,000 list.
At the top of the 2016 guide to Britain and Ireland's richest people are property tycoons the Reuben brothers, owners of London's Millbank Tower and the John Lewis headquarters, who have a fortune of £13.1bn.
Mumbai-born David and Simon Reuben, who also own London Oxford Airport and London Heliport, have increased their fortune by £3.4bn in the past year.
Others on the list include:
Making it onto the Rich List at all requires at least £103m.
Brothers Sri and Gopi Hinduja, who run the Hinduja Group, remain in second place a year on with an unchanged fortune of £13bn.
Completing the top three is Warner Music owner Len Blavatnik, who has £11.59bn. He has dropped two places after a reduction in wealth by £1.58bn.
The Mittals' previous vast wealth of £27.7bn was the biggest fortune achieved by anyone on the list before or since.
Earlier this month it was reported that ArcelorMittal board member Wilbur Ross could be among investors expected to be contacted about buying some of Tata's business interests in the UK.
The family behind Europe's biggest steelmaker has lost more than £2bn in the past year, the annual Sunday Times Rich List has revealed.