Palace was built between 293-303 AD for Roman Emperor Diocletian, who after 'retirement' came to live there. Some legends indicate that Diocletian was from Salonae, near-by center of Provincia Dalmatia.
Palace consists of 2 parts: maritime villa in south part and castrum in north. all representative objects are situated in south side: Peristyle, 3 temples (Jupiter, Cibelle, Venus), Emperor's mausoleum (today Dome of St. Domnius).
In 6th or 7th century town was inhabited by christians who raved Emperors mausoleum and turned it into church. Location of remains of Diocletians body is unknown.
Domnius' body was transfered to new church thanks to Pope.
In 12th century Belltower was added and it was reconstructed in 19th century.