ヨハネス2世コムネノス
Constantine was the elder son of Boris Kalamanos (a claimant for the throne of the Kingdom of Hungary) and his wife, Anna Doukaina (a relative of the Byzantine Emperor John II Komnenos). His paternal grandmother, Euphemia was caught in adultery by her husband, King Coloman of Hungary who never recognised her son (Constantine' father) as his own.