Historical Complex of Split with the Palace of Diocletian

The Roman emperor Diocletian had a heavily fortified palace built as his retirement residence on a peninsula about 6 km south-west of Salona, the chief city of the province of Dalmatia. Work is thought to have begun around 295, after the introduction of the Tetrarchy, and the palace was still unfinished when Diocletian abdicated on 1 May 305. Much of its white limestone came from the nearby island of Brač.

When Salona was largely destroyed in the invasions of the Avars and Slavs in the 7th century, some of its people took refuge inside the palace's strong walls, and a new town began there. The palace has been lived in ever since, with homes and shops built into its basement and walls. The emperor's mausoleum became the Cathedral of Saint Domnius, and in the free medieval commune of the 12th to 14th centuries a Romanesque bell tower was added while houses filled the streets and docks.

After the Middle Ages the palace was virtually unknown in the rest of Europe. The town, where 12th- and 13th-century Romanesque churches, medieval fortifications, 15th-century Gothic palaces and Renaissance and Baroque houses sit on top of the ancient palace, was inscribed as a World Heritage site in 1979.