As head of General Electric from 1981 to 2001, Jack Welch took the company founded by Thomas Edison a century before and brutally transformed it into the biggest US company by market value.
Believing that leaders should appoint lieutenants cleverer than they are, he created a system of managerial excellence that spawned a whole cohort of senior executives, many of whom went on to head other companies. Indirectly, he inspired many more.