Along with the Ardiaei and the Dardani, the Autariatae are mentioned by Strabo in his "Geographica" as one of the three strongest Illyrian peoples in the pre-Roman Balkans. Following defeat during the Celtic invasions of the Balkans in the 4th century, a part of the Autariatae who remained in Bosnia adopted Celtic culture later in their history. Another part moved southwards and after an agreement with the Kingdom of Macedonia, 20,000 settled in the Parorbelian mountain range, in the borderlands between modern southeastern North Macedonia, northern Greece and southwestern Bulgaria.