Arthas Menethil, Crown Prince of Lordaeron and Knight of the Silver Hand, was the son of King Terenas Menethil II and heir to the throne. He was trained as a paladin by Uther the Lightbringer and had a romantic relationship with the kind sorceress Jaina Proudmoore.
Despite his promising beginnings, Arthas became one of the most powerful and evil beings Azeroth would ever know. Taking up the cursed runeblade Frostmourne, he became a death knight, led the Scourge in destroying Lordaeron, and merged with the Lich King.
Arthas claims Frostmourne. Shortly after, he claims his first victim, Muradin Bronzebeard.