1 Kings 11:1-10 NIV
King Solomon, however, loved many foreign women besides Pharaoh’s daughter—Moabites, Ammonites, Edomites, Sidonians and Hittites. They were from nations about which the LORD had told the Israelites, “You must not intermarry with them, because they will surely turn your hearts after their gods.” Nevertheless, Solomon held fast to them in love. He had seven hundred wives of royal birth and three hundred concubines, and his wives led him astray. As Solomon grew old, his wives turned his heart after other gods, and his heart was not fully devoted to the LORD his God, as the heart of David his father had been. He followed Ashtoreth the goddess of the Sidonians, and Molek the detestable god of the Ammonites. So Solomon did evil in the eyes of the LORD; he did not follow the LORD completely, as David his father had done.
On a hill east of Jerusalem, Solomon built a high place for Chemosh the detestable god of Moab, and for Molek the detestable god of the Ammonites. He did the same for all his foreign wives, who burned incense and offered sacrifices to their gods.
The LORD became angry with Solomon because his heart had turned away from the LORD, the God of Israel, who had appeared to him twice. Although he had forbidden Solomon to follow other gods, Solomon did not keep the LORD’s command.
NIV: New International Version