2 Chronicles 34:1-3

Josiah was eight years old when he began to reign, and he reigned thirty-one years in Jerusalem. And he did what was right in the eyes of the LORD, and walked in the ways of David his father; and he did not turn aside to the right hand or to the left. For in the eighth year of his reign, while he was yet a boy, he began to seek the God of David his father, and in the twelfth year he began to purge Judah and Jerusalem of the high places, the Asherim, and the carved and the metal images.