Split is the second-largest city of Croatia and the largest city of the region of Dalmatia. It lies on the eastern shore of the Adriatic Sea, centred on the Roman Palace of the Emperor Diocletian. Spread over a central peninsula and its surroundings, Split's greater area includes the neighboring seaside towns as well. An intraregional transport hub and popular tourist destination, the city is a link to numerous Adriatic islands and the Apennine peninsula.Split is one of the oldest cities in the area. While it is traditionally considered just over 1,700 years old counting from the construction of Diocletian's Palace in 305 CE, archaeological research relating to the original founding of the city as the Greek colony of Aspálathos (Aσπάλαθος) in the 4th century BCE establishes the urban history of the area as being several centuries older. The city turned into a prominent settlement around 650 AD, when it became successor to the ancient capital of the Roman province of Dalmatia, Salona: as after the Sack of Salona by the Avars and Slavs, the fortified Palace of Diocletian was settled by the Roman refugees. Split became a Byzantine city, to later gradually drift into the sphere of the Byzantine vassal, the Republic of Venice, and the Croatian Kingdom, with the Byzantines retaining nominal suzerainty. For much of the High and Late Middle Ages, Split enjoyed autonomy as a free city, caught in the middle of a struggle between Venice and the king of Hungary for control over the Dalmatian cities. Venice eventually prevailed, as Croatia and Hungary were ravaged by Ottoman incursions.