2 Chronicles 34:1-3

Josiah was eight years old when he became king, and he reigned in Jerusalem thirty-one years. He did what was right in the eyes of the LORD and followed the ways of his father David, not turning aside to the right or to the left. In the eighth year of his reign, while he was still young, he began to seek the God of his father David. In his twelfth year he began to purge Judah and Jerusalem of high places, Asherah poles and idols.