Athaliah was Queen of Judah from 842-836 BC. She was the daughter of King Ahab and Queen Jezebel of the northern kingdom of Israel. She also was the wife of King Jehoram of Judah, and the mother of King Ahaziah.
Following Ahaziah's death at the hands of Jehu, Athaliah seized power and killed all members of the royal family who were possible rivals for the throne, except for Joash, the infant son of Ahaziah, who had been rescued by his Aunt Jehosheba.
When Joash was seven years old, Jehoiada the priest conspired to have the young boy crowned in the Temple as king. When Queen Athaliah heard the commotion, she rushed to the Temple to see what was going on, and found the new king surrounded by army officers and people from all over the land rejoicing and blowing trumpets.
Athaliah ripped her clothes in distress and yelled "Treason! Treason!" Jehoida the priest told the army officers to take her out of the Temple and to kill her. She was killed at the Palace stables. Then, Jehoiada and others destroyed a pagan temple of Baal and destroyed pagan idols. Athaliah's story is found in 2 Chronicles 22:10-12, and in chapter 23.
Next person in the Bible: Azariah (named later as Abed-Nego)