When Athaliah the mother of Ahaziah saw that her son was dead, she arose and destroyed all the royal heirs.
2 Kings 11:1
Surrounding context
11:1 When Athaliah the mother of Ahaziah saw that her son was dead, she arose and destroyed all the royal heirs.
11:2 But Jehosheba, the daughter of King Joram, sister of Ahaziah, took Joash the son of Ahaziah, and stole him away from among the king's sons who were being murdered; and they hid him and his nurse in the bedroom, from Athaliah, so that he was not killed.