1 Kings 16:16

And the people that were encamped heard say, Zimri hath conspired, and hath also slain the king: wherefore all Israel [obviously, all the army. Cf. 1 Kings 12:1 , 1 Kings 12:16 , 1 Kings 12:18 ] made Omri, the captain of the host, king over Israel that day in the camp. It was hardly likely they would submit to the usurpation of Zimri. Not only had he occupied a subordinate position, but his murder of all Elah's friends must have made him a host of enemies in the camp. It was the natural thing for them, therefore, to turn to Omri. He had the advantage of being in possession. The captain of the host stood next to the king ( 2 Kings 4:13 ; 2 Samuel 5:8 ; 2 Samuel 19:13 ; 2 Samuel 20:23 ), and twice stepped into his place ( 2 Kings 9:5 ). This history has many parallels in that of the Roman empire.]