RESULTS FOR 2008
Ranking: 98=
Worth: £760m
Source of wealth: Household appliances

Dyson, 60, wants to build a design and engineering school in Bath. The opening, though, has been put back to 2010 and the cost doubled to £56m after a planning battle. Still, his bagless vacuum cleaners, launched in 1983, now have a 46% slice of the British market and a 32% share in America. Cameo appearances of its products on sitcoms such as Friends have helped the Dyson become a must-have product. Profits at Dyson James, though, fell from £103m to £56.7m on nearly £515m sales in 2006. We value the business at £700m. Salaries, dividends and assets, such as a £15m mansion in Gloucestershire and homes in London and France, take the family to £760m after tax.

RESULTS FOR 2008
Ranking: 59
Worth: £1,080m
Source of wealth: Household appliances