Arthas Menethil, Crown Prince of Lordaeron and Knight of the Silver Hand, son of King Terenas Menethil II and heir to the throne. After taking up the cursed runeblade Frostmourne he became a death knight of the Scourge, leading the undead in destroying Lordaeron, Quel'Thalas, and Dalaran. Later he made his way to the Frozen Throne of Icecrown and merged with the Lich King.