Alexander was the most successful Russian reformer since Peter the Great. His most important achievement was the emancipation of serfs in 1861, for which he became known as Alexander the Liberator. The tsar was responsible for numerous other reforms including reorganizing the judicial system, setting up elected local judges, abolishing capital punishment, promoting local self-government through the zemstvo system, imposing universal military service, ending some of the privileges of the nobility, and promoting the universities. Despite these reforms, during his reign, his brutal secret police, known as the Third Section, sent thousands of dissidents into exile in Siberia.