The roots of student unrest in the University reach deep into the nineteenth century. In 1905, a social-democratic organization emerged at the University and called for the overthrow of the Czarist government and the establishment of a republic in Russia. The imperial government repeatedly threatened to close the University. In 1911, in a protest over the introduction of troops onto the campus and mistreatment of certain professors, 130 scientists and professors resigned "en masse", including such prominent men as Nikolay Dimitrievich Zelinskiy, Pyotr Nikolaevich Lebedev, and Sergei Alekseevich Chaplygin; thousands of students were expelled.