Which king of Assyria besieged Samaria in the days of King Hoshea?

Answer: Shalmaneser

In Hoshea's seventh year Shalmaneser king of Assyria besieged Samaria; after three years the Assyrians captured it.

“In the fourth year of Hezekiah’s reign, which was the seventh year of the reign of Hoshea son of Elah over Israel, Shalmaneser king of Assyria marched against Samaria and besieged it.”— 2 Kings 18:9 (BSB)