Who was the last king of Israel before it fell to Assyria?

Answer: Hoshea

Hoshea son of Elah reigned nine years in Samaria; in his ninth year the king of Assyria captured Samaria and exiled Israel.

“In the twelfth year of the reign of Ahaz over Judah, Hoshea son of Elah became king of Israel, and he reigned in Samaria nine years.”— 2 Kings 17:1 (BSB)