Depending on who you ask, Britain’s Labour Party is either soaring, or in free-fall. There is evidence for both propositions, but the reality is messier. Jeremy Corbyn’s leadership should not be viewed as merely one example of a broader flourishing of populist anti-austerity politics across Europe. Corbyn’s victory owed much to the specific and local circumstances of British Labour in summer 2015, as the party reeled from an epochal electoral defeat. Whether Corbyn’s leadership can prosper outside this very specific moment remains an open question.