Vilnius' oldest Baroque church, the large St Kazimieras' Church was built by the Jesuits in 1604-15. Its dome and cross-shaped ground plan, influenced by the Jesuits' Il Jesu Church in Rome, defined a new style for 17th century Lithuanian churches. Under tsarist rule, the church, which is dedicated to Lithuania's patron saint, Prince Casimir Jagiellon, was taken over by the Russian Orthodox Church and given an onion dome. During the First World War the German occupation turned it into the "Museum of Atheism and History of Religion". The onion dome was removed in 1942.
(c) extract from Baltic States & Kaliningrad, Lonely Planet Guide.