Isaiah was the prophet who lived during King Hezekiah’s reign and foretold the defeat of the Assyrian army threatening Jerusalem. His ministry belongs to the turbulent eighth century BCE, when Assyria dominated the ancient Near East.
The opening of the Book of Isaiah places his prophetic activity during the reigns of Uzziah, Jotham, Ahaz, and Hezekiah, kings of Judah. During Hezekiah’s rule, Assyria invaded Judah and besieged Jerusalem under King Sennacherib, traditionally dated to 701 BCE. Isaiah urged Hezekiah not to surrender and presented Jerusalem’s survival as part of God’s judgment and protection.
The account is sometimes confused because Nahum also prophesied against Assyria, but Nahum’s focus is the later fall of Nineveh. Micah was likewise a contemporary of Isaiah and addressed Judah, while Jeremiah belonged to a later generation. Isaiah is therefore the single best answer for the prophet associated with Hezekiah and the promised defeat of Assyria.