Closed by the Tsar in 1832 as part of reprisals for the 1830 insurrection, the university did not reopen until 1915. Under German occupation, studying was forbidden and thousands of clandestine students and teachers were killed. An underground university came into being, and the idea of a "flying university" persisted under communism. Note the Casimir palace in the main courtyard, former seat of a famous military academy, and the lovely Baroque Czapski palace, now an academy of fine arts.