Now King Solomon loved many foreign women. Besides Pharaoh's daughter, he married women from Moab, Ammon, Edom, Sidon, and from among the Hittites.
The LORD had clearly instructed his people not to intermarry with those nations, because the women they married would lead them to worship their gods. Yet Solomon insisted on loving them anyway.
He had seven hundred wives and three hundred concubines. And sure enough, they led his heart away from the LORD.
In Solomon's old age, they turned his heart to worship their gods instead of trusting only in the LORD his God, as his father, David, had done.
Solomon worshiped Ashtoreth, the goddess of the Sidonians, and Molech, the detestable god of the Ammonites.
References for 1 Kings 11:5
Thus, Solomon did what was evil in the LORD's sight; he refused to follow the LORD completely, as his father, David, had done.
On the Mount of Olives, east of Jerusalem, he even built a shrine for Chemosh, the detestable god of Moab, and another for Molech, the detestable god of the Ammonites.
Solomon built such shrines for all his foreign wives to use for burning incense and sacrificing to their gods.