Following the example of his ancestor King David, he did what was pleasing to the Lord.
He destroyed the pagan places of worship, broke the stone pillars, and cut down the images of the goddess Asherah. He also broke in pieces the bronze snake that Moses had made, which was called Nehushtan. Up to that time the people of Israel had burned incense in its honor. 1
References for 2 Kings 18:4
Hezekiah trusted in the Lord, the God of Israel; Judah never had another king like him, either before or after his time.
He was faithful to the Lord and never disobeyed him, but carefully kept all the commands that the Lord had given Moses.
So the Lord was with him, and he was successful in everything he did. He rebelled against the emperor of Assyria and refused to submit to him.
He defeated the Philistines and raided their settlements, from the smallest village to the largest city, including Gaza and its surrounding territory.
In the fourth year of Hezekiah's reign - which was the seventh year of King Hoshea's reign over Israel - Emperor Shalmaneser of Assyria invaded Israel and besieged Samaria.
In the third year of the siege Samaria fell; this was the sixth year of Hezekiah's reign and the ninth year of Hoshea's reign.
The Assyrian emperor took the Israelites to Assyria as prisoners and settled some of them in the city of Halah, some near the Habor River in the district of Gozan, and some in the cities of Media.
References for 2 Kings 18:11
Samaria fell because the Israelites did not obey the Lord their God, but broke the covenant he had made with them and disobeyed all the laws given by Moses, the servant of the Lord. They would not listen and they would not obey.
In the fourteenth year of the reign of King Hezekiah, Sennacherib, the emperor of Assyria, attacked the fortified cities of Judah and conquered them.