1 Kings 16:23-24

23In the thirty-first year of Asa king of Judah, Omri became king over Israel and reigned for twelve years. He reigned six years at Tirzah.

24Omri bought the hill Samaria from Shemer for two talents of silver, and he built a city on the hill [and fortified it], and named the city which he built Samaria, after the owner of the hill, Shemer.