Sir Alan Sugar

Date of birth: 24/3/1947
Industry: Consumer electronics
Estimated worth: £800m

Born in Hackney, east London, Sugar left school at 16 and took on a range of jobs - from civil service statistician to selling car aerials from the back of a van.

The tough-talking businessman has turned into something of a celebrity with his appearances on The Apprentice, a BBC2 reality show.

Known for his ‘you’re fired’ catchphrase, Sugar will be appearing in a TV Comic Relief special of The Apprentice in mid-March.

The Amstrad chairman will be giving celebrities such as Maureen Lipman, Jo Brand, Rupert Everett and Ross Kemp tasks to see how well they cope in a competitive business environment.

In 1968, aged 21, he set up his own business, selling electrical products from intercoms to retractable car antennas and called it Amstrad, (Alan Michael Sugar Trading).

This blossomed into a large public company, famous for selling affordable computers and other home electronics products, as well as having pioneered the Europe-wide satellite receiving market. Of his start-up days, Sugar said: "I had very little money and had to buy and sell for cash. I couldn't get credit."

In 1986, he began to sell PCW8256 word processors at £300 each, and Amstrad's stock market value reached around £1.2bn in the late 1980s (although it is now worth around £110m). In 1991 the entrepreneur also dabbled in football when he announced he'd joined forces with Terry Venables to buy Tottenham Hotspur Football Club, beating off competition from Robert Maxwell and simultaneously saving Tottenham from the brink of bankruptcy. But the Venables-Sugar partnership didn't turn out so sweet and Sugar has admitted his years as Spurs' chairman were "a waste of my life".

Sugar is a key player in the business and media world and one of the UK's most successful entrepreneurs, which was recognised in 2000 when he was knighted for services to industry. He remains head of Amstrad, owner of software firm Viglen among others, and a 13% shareholder of Tottenham Hotspur FC.

He also owns private motors, property in Florida and Spain, and even has his own private plane which he fondly refers to as his "toy plane" as well as several Rolls-Royces. He's been married for over 35 years, has three grown-up children and five grandchildren.

Sugar ranked 71st in the Sunday Times Rich List 2006.