Benghazi fell to Libyan rebel forces in late February 2011 in one of the most dramatic reversals of the Arab Spring — the second-largest city in the country, long a seat of opposition to Muammar Gaddafi's four-decade rule, becoming the first major urban prize claimed by the uprising that had begun in earnest just days earlier.

The fall of Benghazi was significant beyond its immediate military meaning. It created a liberated zone with functional governance ambitions, providing the nascent opposition with a geographic base from which to organize, communicate internationally, and eventually establish the Transitional National Council that Western governments would cautiously recognize as a legitimate interlocutor.

Gaddafi's response to Benghazi's fall was to promise, in terms of remarkable explicitness, to hunt opponents house by house, room by room, alley by alley. The threat was credible: Gaddafi had a forty-year record of eliminating enemies with extreme thoroughness. It was also the explicit threat that triggered the UN Security Council's authorization of a no-fly zone and ultimately the NATO air campaign that would tip the military balance against Gaddafi.

Benghazi's geography — coastal, facing Europe, historically outward-looking in ways that Tripoli's political culture was not — made it a natural base for the international intervention that followed. The city that Gaddafi had treated as a threat for decades became, in 2011, the platform from which his regime's end was organized.

What Benghazi would become after Gaddafi — what any of Libya would become — was a question that the urgency of 2011 left almost entirely unanswered.