Split is the largest and most important city in Dalmatia, the administrative center of Croatia's Split-Dalmatia county. It is situated on a small peninsula on the eastern shores of the Adriatic Sea, in the foothills of Kozjak and Mosor mountains.
Although the beginnings of Split are usually linked to the building of Diocletian's Palace, there is evidence that this area was inhabited as a Greek colony even earlier. Diocletian was a Roman emperor who ruled between A.D. 284 and 305 and was known for his reforms and persecution of Christians. He ordered the work on the palace to begin in 293 in readiness for his retirement from politics in 305. The palace faces the sea on its south side and its walls are 570 to 700 feet (170 to 200 m) long and 50 to 70 feet (15 to 20 m) high, and it encloses an area of 9½ acres (38,000 m²).
This massive structure was long deserted when the first citizens of Split settled inside its walls. In 639, the interior was converted into a town by the citizens of Salona who escaped the destruction of their town by the Avars. Over the centuries, the city has spread out over the surrounding landscape, but even today the palace constitutes the inner core of the city, still inhabited, full of shops, markets, squares, with even a Christian cathedral (formerly Diocletian's mausoleum) inserted in the corridors and floors of the former palace.