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 David his father (forefather) and did not turn aside either to the right or to the left. For in the eighth year of his reign, while he was still young (sixteen), he began to seek after and inquire of the God of his father David; and in the twelfth year he began to purge Judah and Jerusalem of the high places, the Asherim, and the carved and cast images.