Bosnia (Greek: Βοσωνα, romanized: Bosona, Serbo-Croatian: Босна, Bosna) in the Early Middle Ages to early High Middle Ages was a territorially and politically defined South Slavic entity. It was situated, broadly, around the upper and middle course of the Bosna river, between the valleys of the Drina river on the east and the Vrbas river on the west, which comprise a wider area of central and eastern modern-day Bosnia and Herzegovina.