On September 16, 1985, seven years after he had started the company with his friend Steve Wozniak, Steve Jobs resigned as chairman of Apple Computer. Twelve years later to the day, the company announced that he was back.
In the years leading up to his departure, Steve Jobs had been obsessively working on his personal project within the company: the Macintosh. The company's Apple II, designed largely by Steve Wozniak and debuted in 1977, had been hugely profitable, but subsequent systems like the clunky $10,000 Lisa were not as successful.
With his Macintosh team, Jobs set out to create a machine that would be a triumph not only for the company, but for himself, too. He instilled in his team a sense of creativity and rebellion—its said that he hung a pirate flag in their office (which was in a separate building from the rest of the company) and explained that it was better to be a pirate than to join the Navy. He grew increasingly antagonistic toward Apple's other groups, contributing to the fissure that would eventually lead to him leaving the company.
The famous 1984 Superbowl commercial whipped up much anticipation for the Mac, and while it was generally well-received, sales quickly cooled. Jobs began openly clashing with John Sculley, the CEO Jobs himself had lured away from Pepsi just a few years earlier, and in May Sculley stripped Jobs of his managerial duties, giving him a position as Chairman. Jobs spent four months trying to figure out his next move, and on September 16, 1985, he resigned from Apple Computer.
That next move was NeXT Inc, founded with the intention of providing powerful computers for higher education, business, and research purposes. Their expensive machines never took off, however, and after a decade of some significant innovation marred by financial failure, Jobs convinced Apple to acquire NeXT in 1996.
The end of 1996 and the beginning of 1997 were Apple's worst quarters on record, and the board of directors ousted CEO Gil Amelio. Jobs agreed to take the helm in an interim capacity while they searched for a new CEO, and at Macworld Boston that August he was on stage to announce an unexpected new partnership with Microsoft.
Though he had sold his shares at the beginning of the year, Jobs worked tirelessly to chart a new course for the company, and on September 16, 1997, Apple officially announced that he would serve as interim CEO. Twelve years to the day after he had been ousted, Steve Jobs was back at the company he had started. [Wired, All About Steve Jobs, Wikipedia]