The diocese possesses splendid churches and venerable sanctuaries. Of the former the largest and most beautiful are in Vilnius, although many, violently wrested from the Catholics, became Russian Orthodox churches. The cathedral, dedicated to the Blessed Trinity, St. Stanislaus and St. Ladislaus, was erected in the place of a demolished pagan sanctuary in virtue of a Papal Bull of 12 March 1387. Burned down in 1399, it was rebuilt in the Gothic style in 1399 by Grand Duke Vytautas; again destroyed in 1531 and 1662, its restoration was begun in 1769 and finished in 1801. It contains splendid chapels, especially those of St. Casimir and of the Immaculate Conception.