2 Kings 11:19-21

19Jehoiada took with him the officers of army groups, the king's special guards, the palace guards and all the people. They went together to bring the king down from the Lord's temple into the palace. They went into the palace through the gate of the king's royal guards. Then Joash sat on his throne as king.

20All the people were very happy. There was no longer any trouble in Jerusalem now that Athaliah was dead. They had punished her with death at the palace.

21And Joash was seven years old when he began to rule Judah as king.