Then the king of Assyria invaded all the land and came to Samaria, and for three years he besieged it.
We have here the reign and ruin of Hoshea, the last of the kings of Israel, concerning whom observe, I. That, though he forced his way to the crown by treason and murder (as we read Kg2 15:30), yet he gained not the possession of it till seven or eight years after; for it was in the fourth year of Ahaz that he slew Pekah...
Commenting on 2 Kings 17:1-6
Then the king of Assyria came up throughout all the land,.... Of Israel, there being none to oppose his march; Hoshea not daring to come out, and meet him and fight him: and went up to Samaria, and besieged it three years; so long the city held out against him, see Kg2 18:9.
Besieged it three years - It must have been well fortified, well provisioned, and well defended, to have held out so long.