Herodias was the daughter of Aristobulus, a son of Herod the Great's first wife, which made her the niece of both Philip and Antipas. She was married to Philip when she traveled to Rome with him and Antipas. There Antipas became enamored of her and asked for her hand, and she accepted on the condition that he divorce his Nabatean wife, the daughter of King Aretas IV. That divorce provoked Aretas's grudge and, later, his invasion of Perea. The marriage violated Leviticus 20:21, and when John the Baptist publicly denounced it, Herodias hated him from then on. Antipas imprisoned John largely because of her feelings, and he knew John was a holy and just man. At Antipas' birthday celebration, her daughter Salome danced, and Antipas offered her any wish. At her mother's bidding, Salome asked for John's head, and Antipas had the innocent prophet executed. Herodias' influence exposed Antipas' pliable, weak character. Her ambition also helped bring about his downfall. She urged him to follow her brother Agrippa's example and ask Gaius for the title of king. Agrippa had already sent Gaius a letter accusing Antipas of plotting rebellion with the Parthians, so Gaius exiled Antipas to Gaul and gave his territories to Agrippa.