The prerevolutionary strike movement in Russia from 1912-1916 was one of the most spectacular in world labour history. Because labour historians have tended to focus their attention on the revolutionary years of 1905 and 1917, the strike wave before 1917 remains largely ignored. In terms of the number of participants and political demands, however, the prolonged movement was unprecedented. Examining strikes at the factory level, this essay argues that revolutionaries, particularly the Bolsheviks, acted as catalysts for the movement. The presence or absence of revolutionary agitators, even at the shop level, determined whether workers participated in the strike actions.