In January 1905, the Bloody Sunday massacre of protesters in St. Petersburg sparked a spate of civil unrest in the Russian Empire known as the Revolution of 1905. Lenin urged Bolsheviks to take a greater role in the events, encouraging violent insurrection. In doing so, he adopted SR slogans regarding "armed insurrection", "mass terror", and "the expropriation of gentry land", resulting in Menshevik accusations that he had deviated from orthodox Marxism. In turn, he insisted that the Bolsheviks split completely with the Mensheviks; many Bolsheviks refused, and both groups attended the Third RSDLP Congress, held in London in April 1905. Lenin presented many of his ideas in the pamphlet "Two Tactics of Social Democracy in the Democratic Revolution", published in August 1905. Here, he predicted that Russia's liberal bourgeoisie would be sated by a transition to constitutional monarchy and thus betray the revolution; instead he argued that the proletariat would have to build an alliance with the peasantry to overthrow the Tsarist regime and establish the "provisional revolutionary democratic dictatorship of the proletariat and the peasantry."