An Egyptian king contemporary with Hoshea, the last king of the ten-tribe kingdom of Israel. When Hoshea conspired with So against Shalmaneser V and stopped paying tribute to Assyria, Hoshea was imprisoned. (2Ki 17:3, 4) Attempts to identify So with secularly known Egyptian rulers of this general period (such as Osorkon IV or Shabaka) are very uncertain, particularly in view of the uncertainty of Egyptian chronology.​—See CHRONOLOGY.