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Béla IV was the Duke of Styria from 1254 to 1258. He was the eldest son of King Béla III of Hungary and Maria Laskarina, a Byzantine princess. Béla IV succeeded his father as King of Hungary in 1235. In 1254, he invaded Styria and forced the Duke Ottokar II Přemysl to cede the duchy to him. Béla IV ruled Styria until his death in 1270.