2 Chronicles 34:2 (KJV)

Josiah was eight years old when he began to reign, and he reigned in Jerusalem one and thirty years.

And he did that which was right in the sight of the Lord, and walked in the ways of David his father, and declined neither to the right hand, nor 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 groves, and the carved images, and the molten images.

And they brake down the altars of Baalim in his presence; and the images, that were on high above them, he cut down; and the groves, and the carved images, and the molten images, he brake in pieces, and made dust of them, and strowed it upon the graves of them that had sacrificed unto them.