In 295, the Roman emperor Gaius Valerius Aurelius Diocletianus began building a palace in a bay on the Dalmatian coast where he had been born. After his abdication in 305, the retired ruler left Nicomedia and settled down in the palace, which was trapezium-shaped and covered 28,900 square metres, with the intention of seeing out the rest of his days there.
After Diocletian's death, the palace remained under imperial rule. Its transformation into a city began in the 7th century when the inhabitants of Salona and its surroundings took refuge in it from the raids of the Avars and Slavs.
In the tenth and eleventh centuries, Split fell under the rule of the Croatian kings. At the beginning of the twelfth century, like other Dalmatian towns, it came under the rule of Hungarian-Croatian kings. From the beginning of the fifteenth century to half-way through the eighteenth century, it was under Venetian administration. In the nineteenth century, after a short period of French rule, Split became part of the Austro-Hungarian Monarchy. After World War I, Split's role as a cultural, administrative and economic centre became stronger and the number of its inhabitants grew. World War II brought hardship and bombing. However, the period of peace that followed led to the dynamic growth of the city. Split was not directly damaged in the Homeland War, but it took in many refugees and began to stagnate economically.