2 Chronicles 22:10

Now [when] Athaliah the mother of Ahaziah saw that her son [was] dead, she arose and murdered all the {royal descendants} of the house of Judah.

2 Kings 11:1-3

Now Athaliah the mother of Ahaziah saw that her son was dead, so she prepared to destroy all of the offspring of the royal family.

2 Chronicles 22:2-4

Ahaziah [was] forty-two years old when he became king, and he reigned one year in Jerusalem. And the name of his mother [was] Athaliah, the daughter of Omri.

Treasury of Scripture Knowledge

Summary

But when Athaliah the mother of Ahaziah saw that her son was dead, she arose and destroyed all the seed royal of the house of Judah.

Bible References

Athaliah

2 Chronicles 22:2
Ahaziah [was] forty-two years old when he became king, and he reigned one year in Jerusalem. And the name of his mother [was] Athaliah, the daughter of Omri.
2 Kings 11:1
Now Athaliah the mother of Ahaziah saw that her son was dead, so she prepared to destroy all of the offspring of the royal family.