So

From BibleEncyclopedia.Net

sō (סוא, ṣō', although the Hebrew might be pointed סוא, ṣewe'; Assyrian Sib'u; Septuagint Σηγώρ, Sēgṓr, Σωά, Sōá; Manetho, Σεύεχος, Seúechos; Latin Sevechus; Herodotus (ii. 137 ff), Σαβακών, Sabakṓn):

(Nubian, Sabako), an Ethiopian king who brought Egypt under his sway. He was bribed by Hoshea to help him against the Assyrian monarch Shalmaneser (2 Kings 17:4). This was a return to the policy that had been successful in the reign of Jeroboam I.

In all probability the “Sabaeo” of Herodotus, the Shabaka, who founded the Ethiopian dynasty, the XXVth of Egyptian kings. His date is given as 715-707 BC (Flinders Petrie, History of Egypt, III, 281 ff), but we may suppose that before his accession to the throne he was entitled to be designated king, as being actually regent. To this So, Hoshea, king of Israel, made an appeal for assistance to enable him to throw off the yoke of the Assyrian Shalmaneser IV (2 Kings 17:3 ff). But Hoshea's submission to So brought him no advantage, for Shalmaneser came up throughout all the land and laid siege to Samaria. Not long after the fall of Samaria, So ventured upon an eastern campaign, and was defeated by Sargon, the successor of Shalmaneser, in the battle of Raphia in 720 BC.