Kel'Thuzad was the founder of the Cult of the Damned and one of the principal agents of the Lich Kingresponsible for the spreading of the plague of undeath across Lordaeron. Originally a humanmage of the Kirin Tor, Kel'Thuzad was swayed under the influence of the Lich King. After bringing the plague to Lordaeron under the pretense of being under the orders of Mal'Ganis he was slain by Arthas. Arthas (by then a death knight) resurrected him as a lich so he could summon Archimonde the Defiler into Azeroth. Following Arthas' departure for Northrend, Kel'Thuzad was left to command the Scourge of Lordaeron from his necropolis, Naxxramas. Following his first defeat, he and his necropolis moved to Northrend.