Amstrad (Alan Michael Sugar TRADing) grew as a company in the '80s when it started to manufacture computers to rival the big guns of Sinclair and Commodore.
In the '90s, Amstrad began on portable computers but its real success came in the manufacturing of Sky set-top boxes, a business the company still holds onto today.
Last year Sugar sold Amstrad to BSkyB for £125 million. His departure has been described by the man himself as a "planning" move.
From Alan to Alun
Speaking about his exit, Sir Alan Sugar said: "This is a move that has been planned for a while and it's the right time for me to step down from my role at Amstrad.
"The past 40 years have seen Amstrad grow from a start-up business to the success story that it is today, which is credit to the talented and loyal team here."
Amstrad Managing Director Alun Webber who took over the day-to-day running of the company when it moved to BSkyB is to take control.
This won't be the last we see of the Sugar, though, as he still has a number of business with prefix Ams (Amshold, Amsprop, Amsair) and there's the little thing of The Apprentice which, a show which shows no signs of abating.