“Paris is worth a mass,” Henry of Navarre is said to have remarked before he renounced his Protestantism in order to claim the French throne. One of the reasons why the perennial protestor and seeming political puritan, Jeremy Corbyn, won the Labour leadership in 2015 was that his opponents all seemed to believe that Downing Street was worth not only a mass, but a cathedral, a seminary and a host of monks, too. Corbyn’s election literature even came enclosed in an envelope bearing the disclaimer: “Warning: Contains A New Kind of Politics.”

Much of Corbyn’s appeal was in that promise of a new kind of politics. Here was a politician who had avoided the compromises of New Labour and its descendants, who would run the party differently. There would be an end to artful positioning. In its place we would have “honest, straight-talking politics.” The purity was the point. Paris would have to be secured without a mass—or not at all. The seeming lack of the will to put winning first was also why the Conservatives relished the idea of an election against Corbyn. “It’s as if the laws of gravity have been suspended,” one minister reflected shortly after the Islington North MP first became Labour leader.

Then the 2017 election happened, and the laws of gravity turned out to apply after all. Sure, Labour didn’t win, but they came close. The result was even better in the light of 2015’s disaster. The Tories might only have had a narrow majority in the Commons, but most MPs were sitting on super-majorities. For Labour, revival looked like a 10-year project. Now Labour needs just a one-point swing from the Conservatives to form a minority government and a mere three-point swing to win a majority of one. Paris is in sight, no mass required.

Well, up to a point. Like the French king before him, Corbyn showed an unnoticed willingness, if not fully to submit to the old heresies, at least to nod to them.

On Europe, Corbyn has shown more deftness over a longer period of time than he is given credit for. He is a leftish Eurosceptic of long vintage. One family friend joked that he had been “replaced with a duplicate” when he started to say positive things about the EU in the referendum campaign. He has, after all, voted against every European treaty in the Commons during his time as an MP. Britain’s relationship with the EU is, however, a special case—it is perhaps the only issue on which Corbyn is further from the instincts of Labour’s grassroots than his internal opponents in the parliamentary Labour Party. His conduct in the referendum did just enough to appease Labour members—but without conceding on the central issues on which he disagrees with the European project. It was all rather cunningly judged. Labour members, who are, in the main, pro-European—broadly supportive, glad it’s there, but ultimately regarding it as a second-order issue—were sufficiently reassured. But he left himself room to pull off another body-swerve, returning to a more Eurosceptic position in time for the election, all the better to hold on to as many Labour voters who backed a “Leave” vote.

“The Labour leader even compromised on clothing, wearing sharper suits and sporting a neater beard”

On tax, Corbyn, who only two years ago campaigned promising to increase the basic rate, went into the election proposing not merely to leave it alone, but also to lay off even higher-rate payers (the top 15 per cent of earners) except that minority earning over £80,000.

The election perhaps hinged on Corbyn’s most lucrative compromise, over policing. For much of his political career, both as an activist outside Westminster and as an MP, Corbyn has been a reliable opponent of giving the police any more powers, and it’s fair to say they’ve not previously been top of his list of priorities when it comes to resources. But he, and his close ally the Shadow Home Secretary Diane Abbott, both believed that by bringing police cuts into the wider story of anti-austerity politics, they could hurt the Conservatives and Theresa May.

That gambit turned out to be more vital than anyone had imagined. The terrorist attacks, first in Manchester and then, towards the close of the campaign, in London pulled Labour off its preferred themes, which had dominated the contest. The mood in Labour was bleak. One aide believed the attack would allow May—the steadfast former Home Secretary—to “reset” her campaign after her gaffes, return to her home territory of security, and turn fire on Corbyn whom most of the press were, don’t forget, framing as a friend of terrorism in all its guises, from the IRA to Hamas. It was almost bound to be a Conservative boon.

But May’s home turf turned out to have a hole in the ground: and Corbyn, whose first televised appearance at Labour Party conference was railing against the police, emerged as the more authentic-sounding champion of the security services than the longest-serving Home Secretary since 1951.

Corbyn bit his tongue on another security issue: Trident. The anti-disarmament party machine was always one step ahead of him, but he didn’t take the puritan option of openly disavowing the policy; instead he sucked it up, mumbling about collective decision making, while not bothering to disguise his discomfort.

Strikingly, not all of Corbyn’s compromises were deliberate. The omission of a manifesto commitment to end the welfare cap, the issue on which he rebelled against the Labour whip during the leadership contest, and—his rivals believed—thereby sealed the deal, happened not because Corbyn has abandoned his commitment to easing the pain of welfare commitments, but because of a simple oversight: Labour’s welfare team simply forgot to include a pledge, as they took it for granted that a Labour government would lift the cap.

The Labour leader even compromised on clothing, wearing sharper suits and sporting a neater beard. Yes, Corbyn led Labour to their first forward advance since 1997 on a platform offering an expanded role for the state and the trade unions of a kind that many thought doomed to fail. But Corbyn did ultimately decide that Paris was worth a mass, albeit a short one.