He removed the high places, broke down the pillars, and cut down the sacred pole. He broke in pieces the bronze serpent that Moses had made, for until those days the people of Israel had made offerings to it; it was called Nehushtan.
References for 2 Kings 18:4
He trusted in the Lord the God of Israel; so that there was no one like him among all the kings of Judah after him, or among those who were before him.
For he held fast to the Lord; he did not depart from following him but kept the commandments that the Lord commanded Moses.
The Lord was with him; wherever he went, he prospered. He rebelled against the king of Assyria and would not serve him.
He attacked the Philistines as far as Gaza and its territory, from watchtower to fortified city.
In the fourth year of King Hezekiah, which was the seventh year of King Hoshea son of Elah of Israel, King Shalmaneser of Assyria came up against Samaria, besieged it,
and at the end of three years, took it. In the sixth year of Hezekiah, which was the ninth year of King Hoshea of Israel, Samaria was taken.
The king of Assyria carried the Israelites away to Assyria, settled them in Halah, on the Habor, the river of Gozan, and in the cities of the Medes,
because they did not obey the voice of the Lord their God but transgressed his covenant—all that Moses the servant of the Lord had commanded; they neither listened nor obeyed.
In the fourteenth year of King Hezekiah, King Sennacherib of Assyria came up against all the fortified cities of Judah and captured them.
King Hezekiah of Judah sent to the king of Assyria at Lachish, saying, "I have done wrong; withdraw from me; whatever you impose on me I will bear." The king of Assyria demanded of King Hezekiah of Judah three hundred talents of silver and thirty talents of gold.