Athaliah (Hebrew: עֲתַלְיָה) was the queen consort of King Jehoram of Judah and the mother of King Ahaziah of Judah. She is traditionally considered to be the daughter of King Ahab of Israel and Jezebel; thus, she continued in their wicked ways (i.e. the worship of Baal) and spread them to Judah. When Jehoram died, Athaliah's son Ahaziah inherited the throne of Judah. She advised her son Ahaziah and encouraged him to act wickedly.
After Jehu slew Ahaziah, Athaliah massacred all of the royal contenders she could find and usurped the throne of Judah for herself. Unbeknownst to Athaliah, Ahaziah's paternal half-sister Jehosheba managed to save and hide Ahaziah's sole surviving son (thus, Ahaziah's rightful heir) Jehoash.
In the seventh year of Athaliah's illegitimate reign, Jehosheba's husband and priest Jehoiada gathered many guard and bodyguard captains together and formed a pack with them in Jehoash's favor. They then anointed Jehoash as the rightful King of Judah. This was followed by shouts of
Long live the king, trumpets, and jubilation.
Athaliah heard the commotion and personally went to investigate. After realizing what was occurring, Athaliah shouted,
Treason! Treason! Jehoiada and those loyal to the King then captured and executed her.
Jehoiada then restored the covenant between God, king, and the people of Judah. The people destroyed the temple of Baal and executed Baal's priest, putting an end to the wickedness Athaliah brought to Judah, and Jehoash later ordered the restoration of God's Temple, undoing the damage Athaliah's sons did to it.