In the early Neolithic period, the Starčevo, Vučedol and Hvar cultures were scattered around the region. The Iron Age left traces of the Hallstatt culture (early Illyrians) and the La Tène culture (Celts).
In recorded history, the area was inhabited by Liburnians and Illyrians, and since the 4th century BC also colonized in the north by the Celts and along the coast by the Greeks, and later by the Romans. The Southern Illyrian kingdom, Illyris, was a sovereign state in modern day Montenegro and Albania until the Romans conquered it in 168 BC. The Western Empire organized the provinces of Pannonia and Dalmatia, which after its downfall passed to the Huns, the Ostrogoths and then to the Byzantine Empire. The Croats settled there in the early 7th century.