  In 1905, the first Russian revolution broke up, the “dress rehearsal” for the subsequent Bolshevik revolution of 1917, in Lenin’s famous sentence. It found the socialist movement deeply divided. In the West, socialist parties made steady electoral gains, and united superficially in recognition of the moral authority of the Second International but were deeply divided in matters of both principle and tactics. In Russia, there was no direct equivalent to the debate on reform versus revolution: socialists worked underground and were divided mainly on questions of membership and party organisation. The 1905 revolution which broke out after decades of impoverishment, a series of defeats by Russia in the Russo-Japanese war, and subjection to authoritarian violence was not so much a single event as the cumulative result of several years of mass strikes, border unrest, and demonstrations which forced Marxists to put the question of party organisation at the centre of their debates. Luxemburg, recently released from a few months in prison in Zwickau on a charge of undermining the authority of the German emperor, followed the events closely. She published several interventions in which she debated with Lenin on the role of the masses and the party in revolutionary circumstances, and tried to persuade her colleagues in the SPD to adopt the mass strike as a political weapon to advance the cause of workers also in Germany. In December 1905 she smuggled herself on a military train to the Russian part of Poland, and tried to reach Warsaw, where martial law coexisted with a general strike, to resume her work of agitation with the Polish working classes. Within a year she was arrested again, first confined to a police prison in the Warsaw town hall then transferred on grounds of ill-health to the Warsaw Citadel.  There she spent a few months until her release following both her family’s intercessions and payment of the bail, and her reputation as one of the leading activists of the German SPD.  Immediately after her release from prison she went to St Petersburg then Finland, where she met Lenin and wrote one of her most famous pamphlets: “The Mass Strike, the Party and the Trade Unions”, reflecting on the lessons of the 1905 revolution.  The story goes that when she proposed these ideas to the SPD Party Congress of Jena in 1905, August Bebel, one of the party founders, joked that – as he listened to a debate with so much blood and revolution – he kept “glancing occasionally at my boots to see if these weren’t in fact already wading in blood” (Nettl 1966 [2019: 310]).