1 Kings 11:2

and you take some of his daughters for your sons, and his daughters play the harlot with their gods and cause your sons also to play the harlot with their gods.

Now Yahweh was angry with Solomon because his heart was turned away from Yahweh, the God of Israel, who had appeared to him twice,

Now it happened, as though it had been a trivial thing for him to walk in the sins of Jeroboam the son of Nebat, that he took Jezebel the daughter of Ethbaal king of the Sidonians as a wife, and went and served Baal and worshiped him.

All these had taken up foreign women as wives, and some of them had wives by whom they had children.