The tribes of Autariatae and Scordisci are thought to have merged into one in this area after 313BC, since excavations show that the two groups made burials at the same exact grave field in Pecine, near Kostolac. Nine graves of Autariatae dating to 4th century BC and scattered Autariatae and Celtic graves around these earlier graves show that the two groups mixed rather than made war and this resulted in the lower Morava valley becoming a Celto-Thracio-Illyrian interaction zone. The Celtic Invasions of Greece in 279 BC formed the sub-Celtic group of Scordisci who would according to Strabo, defeat and push the powerful Triballians towards the Getae, the Scordisci self-rule in different regions of Serbia gradually ended with the Roman conquest of the Balkans in the 1st century AD.