For most of his career, Jeremy Corbyn, the Labour MP for Islington North since 1983, has been well respected in activist circles and parodied in parliamentary ones. Between 1997 and 2010, under the Labour governments of first Tony Blair and then Gordon Brown, Corbyn voted against his party an unrivaled 428 times. Not that anyone really noticed. When Blair reportedly quipped, in a 1996 interview affirming his own New Labour credentials, that “you don’t have to worry about Jeremy Corbyn suddenly taking over,” the wisecrack never got published, because the reporter reasoned, quite rightly, that nobody would know who this Corbyn person was.

All this changed when, in September 2015, Corbyn suddenly did take over. It happened almost by accident. In the general election that spring, five years of harsh and unpopular austerity policies somehow reinstated David Cameron as Conservative prime minister with a larger share of the vote. In the Labour leadership race that followed, Corbyn was allowed to run, not as a genuine candidate, both he and his colleagues implicitly agreed, but as a relic: a melancholic reminder of Labour’s socialist roots as it chose another ex-Blair or -Brown cabinet minister. “It would be good for the left of the party to see just how few votes would be cast,” a senior Labour figure told The Spectator at the time.

But then the relic came alive. Corbyn received more votes from Labour members than his three opponents combined, running on a campaign against Conservative public sector cuts. Against the wishes of 206 of the 220 Labour MPs, Corbyn was declared leader of the Labour Party, with the largest mandate of any modern equivalent. For his supporters, it heralded the rebirth of the British left. For his critics, Labour had just suffered a second death, dooming itself to electoral oblivion.

Looking back at the shock of Corbyn’s victory, the various convulsions that it triggered in the British political establishment seem almost quaint now compared to what was to come a year later, with the Brexit vote. During his re-election campaign, Cameron had pledged to allow Britain to hold an in/out referendum on European Union membership. What’s equally striking is how little the question of Europe came up in the 2015 Labour leadership debate; the membership seemed to assume, like most of the country, that the Brexit verdict would be a mere blip before Britain moved back to more important matters. Labour had actively condemned Cameron’s referendum promise as irresponsible, and the membership was overwhelmingly pro-EU. But on the one occasion that EU membership did come up, Corbyn did not hide that, unlike his three opponents, he had his doubts. The veteran critic of the EU won regardless.

With the deadline for Brexit negotiations fast approaching, many in Labour see only Corbyn and the messianic fervor of his supporters standing in the way of a resolution to the crisis.

The day after the 2016 referendum, in which Corbyn reticently campaigned for Remain and lost, Labour MPs blamed Corbyn for the result and staged the largest wave of resignations in British history. They also called a new leadership election, and, with 172 Labour MPs saying they had no confidence in him, Corbyn came close to quitting. But he stayed on and, with Brexit now the cornerstone issue of the campaign against him, the membership elected him afresh—by an even bigger margin.