Seth was a Jaredite of the kingdom’s later generations, son of Shiblom (also spelled Shiblon), named in the genealogy that traces the royal line back to Jared (Ether 1:11). His father Shiblom held the throne, but the brother of Shiblom rebelled and started a war across the land, and the brother had all the prophets who foretold the people’s destruction put to death. Wars, famines, and pestilences followed, with great destruction in the days of Shiblom (Ether 11:4, 7, 9).
When Shiblom was slain, Seth was taken into captivity and remained a captive for the rest of his life (Ether 11:9). Seth never held the kingdom. His son Ahah obtained it and reigned the rest of his days, doing much iniquity and shedding much blood, and his days were few (Ether 11:10).