Beloš, was a Serbian prince and Hungarian palatine who served as the regent of Hungary from 1141 until 1146, alongside his sister Helena, mother of the infant King Géza II. Beloš held the title of duke (dux), and ban of Croatia from 1146 until 1157 and briefly in 1163. Beloš, as a member of the Serbian Vukanović dynasty, also briefly ruled his patrimony as the Grand Prince of Serbia in 1162. He lived during a period of Serbian-Hungarian alliance, amid a growing threat from the Byzantines, who had earlier been the overlords of Serbia.

Stephen IV was King of Hungary and Croatia, ascending to the throne between 1163 and 1165, when he usurped the crown of his nephew, Stephen III. He was the third son of Béla II of Hungary, and when his conspiracy against his brother Géza II failed, he was exiled from Hungary in the summer of 1157. He first sought refuge in the Holy Roman Empire, but received no support from Emperor Frederick I. Shortly afterwards he moved to the Byzantine Empire, where he married a niece of Emperor Manuel I Komnenos, Maria Komnene, and converted to the Eastern Orthodox Church.