When Athaliah1 the mother of Ahaziah saw that her son was dead, she proceeded to destroy the whole royal family.
References for 2 Kings 11:1
But Jehosheba, the daughter of King Jehoram and sister of Ahaziah, took Joash2 son of Ahaziah and stole him away from among the royal princes, who were about to be murdered. She put him and his nurse in a bedroom to hide him from Athaliah; so he was not killed.3
References for 2 Kings 11:2
He remained hidden with his nurse at the temple of the LORD for six years while Athaliah ruled the land.
In the seventh year Jehoiada sent for the commanders of units of a hundred, the Carites4 and the guards and had them brought to him at the temple of the LORD. He made a covenant with them and put them under oath at the temple of the LORD. Then he showed them the king's son.
References for 2 Kings 11:4
He commanded them, saying, "This is what you are to do: You who are in the three companies that are going on duty on the Sabbath5--a third of you guarding the royal palace,6
References for 2 Kings 11:5
a third at the Sur Gate, and a third at the gate behind the guard, who take turns guarding the temple--
and you who are in the other two companies that normally go off Sabbath duty are all to guard the temple for the king.
Station yourselves around the king, each man with his weapon in his hand. Anyone who approaches your ranks must be put to death. Stay close to the king wherever he goes."
References for 2 Kings 11:8
The commanders of units of a hundred did just as Jehoiada the priest ordered. Each one took his men--those who were going on duty on the Sabbath and those who were going off duty--and came to Jehoiada the priest.
Then he gave the commanders the spears and shields7 that had belonged to King David and that were in the temple of the LORD.
References for 2 Kings 11:10
The guards, each with his weapon in his hand, stationed themselves around the king--near the altar and the temple, from the south side to the north side of the temple.
Jehoiada brought out the king's son and put the crown on him; he presented him with a copy of the covenant8 and proclaimed him king. They anointed9 him, and the people clapped their hands10 and shouted, "Long live the king!"11
References for 2 Kings 11:12
When Athaliah heard the noise made by the guards and the people, she went to the people at the temple of the LORD.
She looked and there was the king, standing by the pillar,12 as the custom was. The officers and the trumpeters were beside the king, and all the people of the land were rejoicing and blowing trumpets.13 Then Athaliah tore14 her robes and called out, "Treason! Treason!"15
References for 2 Kings 11:14
Jehoiada the priest ordered the commanders of units of a hundred, who were in charge of the troops: "Bring her out between the ranks and put to the sword anyone who follows her." For the priest had said, "She must not be put to death in the temple16 of the LORD."
References for 2 Kings 11:15
So they seized her as she reached the place where the horses enter17 the palace grounds, and there she was put to death.18
References for 2 Kings 11:16