This relief shows King Sargon on the left, larger than life size, receiving his chief official (Tartan), on the right. It came from the south-east facade of Sargon's palace in Khorsabad, north of Nineveh, which he built to commemorate his victories.
Sargon completed the capture of Samaria, the capital of the northern kingdom of Israel. Shalmaneser V began the siege, but died before it was completed.
"King Shalmaneser (V) of Assyria came up against him (Hoshea); Hoshea became his vassal, and paid him tribute. But the king of Assyria found treachery in Hoshea; for he had sent messengers to King So of Egypt, and offered no tribute to the king of Assyria, as he had done year by year; therefore the king of Assyria confined him and imprisoned him. Then the king of Assyria invaded all the land and came to Samaria and besieged it. In the ninth year of Hoshea the king of Assyria (Sargon) captured Samaria; he carried the Israelites away to Assyria. He placed them in Halah, on the Habor, the river of Gozan, and in the cities of the Medes." (2 Kg 17:3-6)
"The king of Assyria (Sargon) brought people from Babylon ..., and placed them in the cities of Samaria in place of the people of Israel; they took possession of Samaria, and settled in its cities." (2 Kg 17:24)
Sargon's annals say this, "At the beginning of my rule, in my first year I (Sargon) captured Samaria, I surrounded and carried away as prisoners 27,290 of its inhabitants, together with their chariots ... and the gods in whom they trusted. From them I equipped 200 chariots for my army units, while the rest I made to take up their lot within Assyria. I restored the city of Samaria and made it more habitable then before. I brought into it people from the countries conquered by my own hands. My official I set over them as district governor and reckoned them as people of Assyria itself." (Nimrud Prism IV 25-41)
Another inscription of Sargon says, "Azuri, king of Ashdod, planned in his heart not to pay tribute. In my anger I marched against Ashdod with my usual bodyguard. I conquered Ashdod, and Gath. I took their treasures and their people. I settled in them people from lands of the east. I took tribute from Philistia, Judah, Edom and Moab."
This is what is described in Is 20:1, "In the year that the commander in chief, who was sent by King Sargon the king of Assyria, came to Ashdod and fought against it and took it ... ". This event is used to date Isaiah's message to Egypt (711 BC)
This passage in Isaiah was the only known mention of Sargon until the discovery of Sargon's palace in 1842. He was thought to be a non-existent before them. This was used to discredit the Bible.