Split is one of the oldest cities in the area. While traditionally considered just over 1,700 years old, counting from the construction of Diocletian's Palace in 305 CE, the city was in fact founded as the Greek colony of Aspálathos (Aσπάλαθος) in the 3rd or 2nd century BCE. It became a prominent settlement around 650 CE, when it succeeded 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 and during the early modern period Split remained a Venetian city, a heavily fortified outpost surrounded by Ottoman territory. Eventually, its hinterland was won from the Ottomans in the Morean War of 1699, and in 1797, as Venice fell to Napoleon, the Treaty of Campo Formio rendered the city to the Habsburg Monarchy. In 1805, the Peace of Pressburg added it to the Napoleonic Kingdom of Italy, and in 1806, it was included directly in the French Empire, becoming part of the Illyrian Provinces in 1809. After being occupied in 1813, it was eventually granted to the Austrian Empire following the Congress of Vienna, where the city remained a part of the Austrian Kingdom of Dalmatia until the fall of Austria-Hungary in 1918 and the formation of Yugoslavia. During World War II, the city was annexed by Italy, then liberated by the Partisans after the Italian capitulation in 1943. It was then re-occupied by Germany, which granted it to its puppet Independent State of Croatia. The city was liberated again by the Partisans in 1944, and was included in the post-war Federal Yugoslavia, as part of its republic of Croatia. In 1991 Croatia seceded from Yugoslavia amid the Croatian War of Independence.