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 and is spread over a central peninsula and its surroundings. An intraregional transport hub and popular tourist destination, the city is linked to the Adriatic islands and the Apennine peninsula.
Home to Diocletian's Palace, built for the Roman emperor in 305 CE, the city was founded as the Greek colony of Aspálathos (Aσπάλαθος) in the 3rd or 2nd century BC. It became a prominent settlement around 650 CE when it succeeded the ancient capital of the Roman province of Dalmatia, Salona. 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 Republic of Venice and the Kingdom of Croatia, 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. 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 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.
Although the beginnings of Split are traditionally associated with the construction of Diocletian's Palace in 305 CE, the city was founded several centuries earlier as the Greek colony of Aspálathos, or Spálathos. It was a colony of the polis of Issa, the modern-day town of Vis, itself a colony of the Sicilian city of Syracuse. The exact year the city was founded is not known, but it's estimated to have been in the 3rd or 2nd century BCE. The Greek settlement lived off trade with the surrounding Illyrian tribes, mostly the Delmatae.
After the Illyrian Wars of 229 and 219 BCE, the city of Salona, only a short distance from Spálathos, became the capital of the Roman Province of Dalmatia. The history of Spálathos becomes obscure for a while at this point, being overshadowed by that of nearby Salona, to which it would later become successor. The Roman Emperor Diocletian (ruled 284 to 305 CE) in 293 CE began the construction of an opulent and heavily fortified palace fronting the sea, near his home town of Salona, selecting the site of Spálathos (or Spalatum in Latin). The Palace was built as a massive structure, much like a Roman military fortress. The palace and the city of Spalatum which formed its surroundings were at times inhabited by a population as large as 8,000 to 10,000 people.
Between 475 and 480 the Palace hosted Flavius Julius Nepos, the last recognised Emperor of the Western Roman Empire - despite Odoacer having abolished the Western Imperial throne with the deposition of Romulus Augustulus in 476. In 493 CE Salona, along with most of Dalmatia, was lost to the Ostrogothic Kingdom. However, in 535-536 CE the Emperor Justinian the Great regained Dalmatia to the by-then Byzantine Empire.
The Pannonian Avars sacked and destroyed Salona in 639 CE; the surviving Romans fled to the nearby islands. The Dalmatian region and its shores were at this time settled by tribes of Croats, a South Slavic people subservient to the Avar khagans. The Salonitans regained the land under Severus the Great in 650 CE and settled the 300-year-old Palace of Diocletian, which could not be effectively besieged by the Slavic tribes of the mainland. The Emperor Constans II granted them an Imperial mandate to establish themselves in the Palace as the City of Spalatum, which imposed upon the Croatian Slavs - at the time alied of Byzantium against the Avars - a cessation of hostilities. The Temple of Jupiter was rededicated it to the Virgin Mary and the remains of the popular Saint Domnius were recovered from the ruins of Salona, later establishing the Cathedral of Saint Domnius as new seat of the Archbishop of Salona. In 1100, the bell tower which became the main symbol of the city was constructed and dedicated to Saint Domnius, by then regarded as the patron saint of the city.