2 Chronicles 34:1-3

Josiah was eight years old when he became king, and he reigned for thirty-one years in Jerusalem.

He did what was right in the sight of the Lord, and walked in the ways of his father David and did not turn aside to the right or the left.

For in the eighth year of his reign while he was still a youth, he began to seek the God of his father David; and in the twelfth year he began to purge Judah and Jerusalem of the high places, the Asherim, the carved images, and the cast metal images.