Just before Thanksgiving, a Silicon Valley giant appeared to implode before our eyes. A boardroom coup at OpenAI, the world’s hottest artificial intelligence company, pushed out its charismatic leader, Sam Altman.

At the time, the ouster — and Altman’s roller-coaster ride to reclaim his job as C.E.O. — seemed sudden. In reality, it was more than a decade in the making. A.I. had been simmering in the tech world, as powerful figures poured money into research and fought with one another over heady questions of humanity, philosophy and power.

This week, with our colleagues Mike Isaac and Nico Grant, we published a series recounting the recent history of A.I. and looking ahead to its future. In today’s newsletter, we explain what we learned.

Powerful tech leaders — including Altman, Elon Musk and the Google co-founder Larry Page — were developing A.I. systems for years before the technology went mainstream. The men bickered over whether it would end up harming the world; some, including Musk, feared that A.I. would turn dystopian science fiction into reality, with computers becoming smart enough to escape human control.