What does 2 Kings 18:1-12 mean?

In the third year of Hoshea son of Elah, king of Israel, Hezekiah the son of Ahaz, king of Judah, began to reign. He was twenty-five years old when he began to reign, and he reigned twenty-nine years in Jerusalem. His mother’s name was Abi the daughter of Zechariah. And he did what was right in the eyes of the LORD, according to all that David his father had done. He removed the high places and broke the pillars and cut down the Asherah. And 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). He trusted in the LORD, the God of Israel, so that there was none like him among all the kings of Judah after him, nor 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. And the LORD was with him; wherever he went out, he prospered. He rebelled against the king of Assyria and would not serve him. He struck down 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 Hoshea son of Elah, king of Israel, Shalmaneser king of Assyria came up against Samaria and besieged it, and at the end of three years he took it. In the sixth year of Hezekiah, which was the ninth year of Hoshea king of Israel, Samaria was taken. The king of Assyria carried the Israelites away to Assyria and put them in Halah, and 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, even all that Moses the servant of the LORD commanded. They neither listened nor obeyed.

English Standard Version (ESV)