Lich King

The Lich King's History
The entity known as the Lich King is actually a fusion of the orc warlock Ner'zhul, and the human paladin turned death knight, Arthas Menethil. Ner'zhul, a servant of the powerful demon Kil'jaeden, was a major leader of the Orcish Horde during the orc invasion of the world of Azeroth. Near the end of the Second War between the Horde and the Alliance of Azeroth, Ner'zhul set about building portals to other worlds, madly hoping to lead a mass invasion through these portals. His plans were interrupted by a reprisal by the Alliance, disrupting the portals and causing them to rip apart the orc homeworld of Draenor. Ner'zhul narrowly escaped through one of his portals, ending up on the Legion's homeworld.

Here, Kil'jaeden punished Ner'zhul severely for his failure, destroying his physical body and torturing his soul. Eventually, Kil'jaeden decided to give Ner'zhul another chance. Binding Ner'zhul's soul to a mystical suit of armor, which he imprisoned in a block of ice, Kil'jaeden dispatched the warlock to Azeroth, where he landed in the frozen land of Northrend. Here, Ner'zhul discovered he possessed untold mental powers, as well as the ability to use a magic plague to rise creatures from the dead as his personal army. Thus was the first Lich King born, beginning his quest to replace all life on Azeroth with his undead minions.

The champion Ner'zhul chose to lead his army, as well as aid the Lich King in escaping his frozen prison, came in the form of Prince Arthas, son of King Terenas of Lordaeron. Serving as a paladin of the Silver Hand, Arthas at first fought against the Undead Scourge, but soon became obsessed with driving them out and protecting his people at any cost. In Northrend, Arthas discovered the runeblade Frostmourne, which he believed would aid him in destroying the undead.

In fact, the runeblade had been planted by the Lich King, who sought to corrupt and control Arthas. He succeeded, and Arthas murdered his own father in cold blood upon his return. Arthas became the first death knight of the Scourge, slaying many and destroying several powerful nations. But his true destiny was yet to unfold. Advised by his close "friend", the lich Kel'thuzad, Arthas succeeded in overthrowing the Lich King's demonic supervisors, the dreadlords, and undoing the Burning Legion's invasion of Azeroth, which Kil'jaeden had planned on using the Scourge for.

Ultimately, Arthas journeyed back to Northrend, defeating Illidan Stormrage, who was staging an attempt at destroying the Lich King. Arthas shattered the Frozen Throne and put on the Lich King's armor, merging with Ner'zhul's spirit to create an entity with Arthas' form, but the combined minds of Ner'zhul and Arthas. More powerful than ever, the Lich King now wages war with the intention of annihilating the living.