841-835 BC evil reign start to finish
1When Athaliah the mother of Ahaziah saw that her son was dead, she rose and destroyed all the royal offspring. 2But Jehosheba, the daughter of King Joram, sister of Ahaziah, took Joash the son of Ahaziah and stole him from among the king’s sons who were being put to death, and placed him and his nurse in the bedroom. So they hid him from Athaliah, and he was not put to death.
2 Kings 11:1,2
10Now when Athaliah the mother of Ahaziah saw that her son was dead, she rose and destroyed all the royal offspring of the house of Judah. 11But Jehoshabeath the king’s daughter took Joash the son of Ahaziah, and stole him from among the king’s sons who were being put to death, and placed him and his nurse in the bedroom. So Jehoshabeath, the daughter of King Jehoram, the wife of Jehoiada the priest (for she was the sister of Ahaziah), hid him from Athaliah so that she would not put him to death.12He was hidden with them in the house of God six years while Athaliah reigned over the land.