2 Chronicles 34:1-3

Josiah was eight years old when he began to reign; and he reigned thirty and one years in Jerusalem. And he did that which was right in the eyes of Jehovah, and walked in the ways of David his father, and turned not aside to the right hand or to the left. For in the eighth year of his reign, while he was yet young, he began to seek after the God of David his father; and in the twelfth year he began to purge Judah and Jerusalem from the high places, and the Asherim, and the graven images, and the molten images.