Béla III of Hungary
Margaret was the eldest daughter of Béla III of Hungary and his first wife Agnes of Antioch. She was a younger sister of Emeric, King of Hungary. Her younger siblings were Andrew II of Hungary and Constance of Hungary. Two other siblings, Solomon and Stephen, are mentioned in the standard reference work on the genealogy of medieval European aristocracy, "Europäische Stammtafeln" (1978–1995) by Detlev Schwennicke. They reportedly died young.