Diocletian's Palace (Croatian: Dioklecijanova palača) is a building in the centre of Split, built for the Emperor Diocletian (a native of Dalmatia) at the turn of the 4th century. On the intersection of two main roads, cardo and decumanus, there is a monumental court Peristyle, from which the only access to Cathedral of St. Domnius is to the east.
The Cathedral of St. Dominus is composed of three different sections of different ages. The main part is Emperor Diocletian's mausoleum, which dates from the end of the 3rd century. The mausoleum was built like the rest of the palace with white local limestone and marble of high quality, most of which was from quarries on the nearby island of Brač, with tuff (rock consisting of consolidated volcanic ash) taken from the nearby river Jadro beds, and with brick made in Salonitan and other factories.
Later, in the 17th century a chorus was added to the eastern side of the mausoleum. For that purpose the eastern wall of the mausoleum was torn down in order to unify the two chambers. The Bell Tower was constructed in the year 1100 AD, in the Romanesque style. Extensive rebuilding in 1908 radically changed the Bell Tower, and many of the original Romanesque sculptures were removed.