Ahaziah was 22 years old when he became king, and he reigned for one year in Jerusalem. His mother was Athaliah, Omri's granddaughter.

During the thirty-sixth year of Asa's reign, King Baasha of Israel invaded Judah and interdicted Ramah by building fortifications around it so no one could enter or leave to join King Asa of Judah.

In the eighth year of his reign, while he was still young, he began to seek the God of his ancestor David. In the twelfth year of his reign, he began to remove the high places, Asherim, carved images, and cast images from Judah and Jerusalem.