In the twenty and seventh year of Asa king of Judah did Zimri reign seven days in Tirzah. And the people were encamped against Gibbethon, which belonged to the Philistines.
1 Kings 16:16
And the people that were encamped heard say, Zimri hath conspired, and hath also slain the king: wherefore all Israel made Omri, the captain of the host, king over Israel that day in the camp.