This weekend marked one year since the founding of Momentum, the organization which grew from the campaign to elect Jeremy Corbyn as Labour leader.

In its first twelve months the fledging political movement made plenty of enemies: from being dubbed “a rabble” by party deputy leader Tom Watson to a millionaire Labour donor’s comparisons with “Nazi stormtroopers” and even undercover investigations by both Channel 4 and the BBC.

Despite these attacks, Momentum has quickly developed into one of the most important institutions on the British left, mobilizing thousands as the driving force behind Corbyn’s successful re-election campaign.