Časlav (, ; 890s – 960) was Prince of the Serbs from 927 until his death in 960. He significantly expanded the Serbian Principality when he managed to unite several Slavic tribes, stretching his realm over the shores of the Adriatic Sea, the Sava river and the Morava valley. He successfully fought off the Magyars, who had crossed the Carpathians and ravaged Central Europe, when they invaded Bosnia. Časlav is remembered, alongside his predecessor Vlastimir, as founders of Serbia in the Middle Ages. Časlav was the son of Klonimir, a son of Strojimir who ruled as co-prince in 851–880. He belongs to the first Serbian dynasty, the Vlastimirovićs (ruling since the early 7th century), and is the last known ruler of the family. His mother was a Bulgarian noblewoman chosen as wife of Klonimir by Boris I of Bulgaria himself. Background After the death of Prince Vlastimir, Serbia was an oligarchy ruled by his three sons: Mutimir, Gojnik and Strojimir, although Mutimir, the eldest, had supreme rule. In the 880s, Mutimir seized the throne for himself, exiling his brothers and Klonimir, who was Strojimir's son, to the First Bulgarian Empire, to the court of Boris I. This was most likely due to treachery. Petar, the son of Gojnik, was kept at the Serbian court of Mutimir for political reasons, but he soon fled to Croatia. When Mutimir died, his son Pribislav inherited the rule, but he only ruled for a year; Petar returned and defeated him in battle and seized the throne; Pribislav fled to Croatia with his brothers Bran and Stefan. Bran was defeated, captured and blinded (blinding was a Byzantine tradition meant to disqualify a person from taking the throne). In 896, Klonimir returned from Bulgaria, backed by Boris I, taking the important stronghold of Destinikon. Klonimir was defeated and killed. The Byzantine–Bulgarian Wars made the Bulgarian Empire de facto the most powerful Empire of Southeast Europe. The Bulgarians won after invading at the right time; they met little resistance in the north because of the Byzantines fighting the Arabs in Anatolia. Early life Časlav was born in the 890s, but before 896, in Preslav, the capital of the First Bulgarian Empire, growing up at the court of Simeon I the Great. His father was Klonimir, and his mother was a Bulgarian noblewoman. In 924, Časlav was sent to Serbia with a large Bulgarian army. The army ravaged