Part of a detailed report of the Assyrian campaign to Ashdod survives on a very fragmentary annal prism discovered at Nineveh that was likely edited in 711 BCE. With relation to affairs in Ashdod, it tells of Sargon II marching at the head of his royal contingent to put down the rebellion that had broken out in the city-

“In the ninth year of my reign, I ma[rched] to [Ashdod that is on the coast] of the Great Sea […] Ashdod […] (A break of a few lines) Because of [the crimes he committed…I removed him] from Ash[dod]…”

This event is also mentioned in Isaiah 20-1-

“In the year that the commander in chief, who was sent by Sargon the king of Assyria, came to Ashdod and fought against it and captured it.”

Mordechai Cogan, The Raging Torrent, Carta, Jerusalem, 2008. p.103-105.