Spalatum or Aspalathos (Greek: Ασπάλαθος): port in Dalmatia, famous as residence of the retired emperor Diocletian, modern Split.
History
Ruins of Spalatum today
s.III-II BCE: Aspalathos founded, probably as colony of Issa, which in turn was a Syracusan settlement from the fourth century BCE
Rome's Illyrian Wars (229-228, 220-219, 168-167 BCE) brought Aspalathos into the Roman zone of influence; the Romans converted nearby Salona into the capital of their new province of Dalmatia
In 305 CE, the emperor Diocletian, who had been shared the empire with Maximian, retired to a fortified palace he had built (in 293) in what was by now known as Spalatum.
Model of Diocletian's palace
Dimensions of the palace: more than 170 meters wide, more than 200 meters long; walls of 15 meters high; enclosing some 38,000 square meters
After Diocletian's death in 311, the palace was no longer used, but one of the last West-Roman emperors, Julius Nepos, lived here until 480