So was the Egyptian king to whom Hoshea, king of Israel, appealed for help against the Assyrian ruler Shalmaneser. He is probably to be identified with Shabaka, the Ethiopian ruler associated with Egypt’s Twenty-fifth Dynasty.
Hoshea appealed to So in an attempt to throw off Assyrian control. The appeal brought no advantage, and Shalmaneser proceeded against the land and besieged Samaria.
The sources identify So in probability with the Sabaeo or Shabaka of other records. After Samaria fell, he later undertook an eastern campaign and was defeated by Sargon at Raphia.