Jupiter’s temple is a temple dedicated to the god Jupiter main deity of the ancient Romans. Located near the Peristyle, the central square of the palace. It was built during the entire construction of Diocletian’s Palace, later became St. fonts. John. At the entrance to the temple is one of the two sphinxes brought out of Egypt by order of Emperor Diocletian.

Temple of Jupiter was constructed from the 295th until 305 However, as part of the palace of Emperor Diocletian. Was probably dedicated to the supreme Roman deity and the divine father Diocletian Jupiter. Temple is located west of the central part of the palace which was the religious part, and to which came the solemn approach. It is known that the car came 305th The Nikomedije from the palace, and then stop the many papers, and parts of the temple remained incomplete.

During late Antiquity and Middle Ages, the temple was converted into a baptistery, a crypt dedicated to St. Thomas. In the thirteenth century baptismal font gets well. At one of the carved marble panel is the oldest version of the Croatian King Kresimir IV or Zvonimir. In the interior are preserved two sarcophagi in which they buried Split Archbishop John and Lawrence. Inside there is a large Mestrovic statue of St John. The vault in the 11th was built early Romanesque bell tower was removed around the 1840th in accordance with the then classical aspirations. In the early 20th century (1907.) removed a few houses on the western and southern sides, so that the temple today released the new works, except those on the northwest corner that is still leaning one house. Those years are made with durable and meet the reconstruction of the surface cement mortar.