8. Jack Welch

8. JACK WELCH Born in Salem, Massachusetts, the son of a rail road conductor, he studied chemical engineering at the university of Massachusetts, gaining a PhD in the same subject from the university of Illinois. He joined General Electric's plastics division in 1960. At age 33 he became one of the company's youngest general managers and in December 1980, after a little over twenty years in the company, he was named GE's eighth CEO, the youngest in the company's history. GE's financial success came at the expense of extensive layoffs. During the process of streamlining the company, over 100,000 workers lost their job. His perceived ruthlessness earned him the moniker 'Neutron Jack'. Since retiring Jack Welch is busy as a consultant to a number of Fortune 500 firms. He also wrote his memoirs: Jack: Straight from the Gut, which was published in 2001; and with Suzy Welch he wrote Winning: The Ultimate Business How-To Book in 2005. Jack Welch arrives for the 20th Anniversary Celebration of 'Literacy Partners' | Photograph: Scott Eells/Getty Images Also read: Success tips of the world's best CEO