What does 2 Kings 18:9 mean?

During Hezekiah's fourth year as king (which was Hoshea's seventh year as king of Israel), Shalmaneser, king of Assyria, attacked Samaria and laid siege to it. 2 Kings 18:9 - Modern Text Bible

(The timeline connects Judah and Israel, showing that while Hezekiah was ruling well, Israel was under attack from Assyria.)