Hezekiah, Ahaz's son, became king of Judah in the third year of Israel's King Hoshea, Elah's son.
References for 2 Kings 18:1
He was 25 years old when he became king, and he ruled twenty-nine years in Jerusalem. His mother's name was Abi; she was Zechariah's daughter.
References for 2 Kings 18:2
Hezekiah did what was right in the LORD's eyes, just as his ancestor David had done.
He removed the shrines. He smashed the sacred pillars and cut down the sacred pole. He crushed the bronze snake that Moses made, because up to that point the Israelites had been burning incense to it. (The snake was named Nehushtan.)
References for 2 Kings 18:4
Hezekiah trusted in the LORD, Israel's God. There was no one like him among all of Judah's kings—not before him and not after him.
He clung to the LORD and never deviated from him. He kept the commandments that the LORD had commanded Moses.