Stephen III of Hungary

Stephen III
Stephen III's seal
King of Hungary and Croatia contested by Ladislaus II (1162–63), and by Stephen IV (1163–65)
Reign	1162–1172
Coronation	June 1162
Predecessor	Géza II
Successor	Béla III
Born	Summer of 1147
Died	4 March 1172 (aged 24–25)
Burial	Esztergom
Spouse	Agnes of Austria
Issue Detail	Béla (died young) Unnamed son
Dynasty	Árpád dynasty
Father	Géza II of Hungary
Mother	Euphrosyne of Kiev
Religion	Roman Catholic

Stephen III (Hungarian: István, Croatian: Stjepan, Slovak: Štefan; summer of 1147 – 4 March 1172) was King of Hungary and Croatia between 1162 and 1172. He was crowned king in early June 1162, shortly after the death of his father, Géza II. However, his two uncles, Ladislaus and Stephen, who had joined the court of the Byzantine Empire, challenged his right to the crown. Only six weeks after his coronation, the Byzantine Emperor Manuel I Komnenos launched an expedition against Hungary, forcing the Hungarian lords to accept Ladislaus' rule. Stephen sought refuge in Austria, but returned and seized Pressburg (now Bratislava in Slovakia). Ladislaus, who died on 14 January 1163, was succeeded by Stephen's younger uncle and namesake, Stephen IV, without resistance, but his rule was unpopular. The young Stephen defeated his uncle on 19 June 1163 and expelled him from Hungary.

Stephen IV attempted to regain his throne with Emperor Manuel I's support, but the latter made peace with Stephen III. He agreed to send his younger brother, Béla, to Constantinople and to allow the Byzantines to seize Béla's duchy, which included Croatia, Dalmatia and Sirmium. In an attempt to recapture these territories, Stephen III waged wars against the Byzantine Empire between 1164 and 1167, but could not defeat the Byzantines.