When he joined the board of Apple in June 1996, Edgar S. Woolard Jr.was nearing the end of his career at the chemical giant DuPont and might have been expected to offer little more than a bit of friendly advice to the computer company.

Instead, he quickly concluded that Apple was in “a total death dive.” Within 13 months, Woolard became the board’s de facto leader, organized the ouster of Gil Amelio as chairman and chief executive in July 1997, and brought back Apple co-founder Steve Jobs, initially as an adviser and later as CEO.