Ner'zhul (also known as the Lich King later) is a fictional character in the Warcraft universe — a fictional universe in which a series of games and books are set.

Biography (as Ner'zhul the Orc)

Ner'zhul was introduced in Warcraft II: The Tides of Darkness. He was the first Orc to make a pact with the Demon Kil'jaeden and was responsible for bringing the demonic Bloodlust upon the Orcs that turned them into killing machines. This Bloodlust was instilled in the Orcs by drinking blood of the Pit Lord Mannoroth, in exchange for their services in conquering Azeroth and the Human kingdom. Kiljaeden is a Supreme Demon Lord originated from the Twisting Nether in the fantasy Warcraft Universe. ...

Kil'jaeden taught Ner'Zhul the art of Warlock magic, which replaced the Orc's elemental Shamanism. Ner'Zhul in turn trained other Orcs in the ways of Warlock magic. His most prominent apprentice is Gul'dan. Later, Ner'zhul wanted to break his pact with the Demons and keep his people from killing each other. The reason for this is because he wants an army of his own for the purpose of conquering new worlds. Ner'zhul also opened many portals to other worlds from the Orcish homeworld of Draenor; eventually causing Draenor to shatter and fall apart due to the instability of energy created by the rifts. Kiljaeden is a Supreme Demon Lord originated from the Twisting Nether in the fantasy Warcraft Universe. ... GulDan the Destroyer was NerZhuls most prominent students, and soon became better than NerZhul himself. ... Draenor is a planet in the Warcraft universe — a fictional universe in which a series of games and books are set. ...

For his insolence his body was destroyed and his spirit was placed in a magical case of ice. This was sent to crash on the continent of Northrend, becoming buried deep in the ground. Ner'Zhul was to become the Lich King - he was to engineer an Undead Scourge to do what the Orcs failed to do - as his punishment by the Burning Legion. The Scourge is a race in the fantasy Warcraft Universe. ...

The Lich King, Leader of the Scourge

As the Lich King, Ner'zhul recruited Acolytes and Kel'Thuzad to assist him in creating the Plague. The Plague later spread across the Human lands of Lordaeron and its neighbors. KelThuzad is a fictional character in the Warcraft fantasy universe. ...

The events that happened in Warcraft III led to Prince Arthas Menethil going to Northrend to find a solution to the progressing Undead legion in his homelands. Muradin Bronzebeard of the Dwarves told Arthas about a legendary runeblade, Frostmourne that can save his people. Arthas Menethil (also known as Prince Arthas or Death Knight) is a fictional character in the Warcraft universe — a fictional universe in which a series of games and books are set. ... Warcraft: Orcs & Humans is a real-time strategy computer game developed and published by Blizzard Entertainment in 1994. ...

Arthas who was desperate for a solution and having no patience, extracted the Frostmourne and thereby letting the Lich King have full control over him.

In Warcraft III: The Frozen Throne, Ner'zhul the Lich King was under attack by Illidan Stormrage who tried to melt Northrend in order to destroy Ner'zhul. Illidan was under the orders of Kil'jaeden who wanted Ner'zhul dead for not fulfilling the Legion's objectives - Ner'zhul created the Undead Scourge for himself as it turns out. Illidan Stormrage (also known as the Demon Hunter) is a fictional character in the Warcraft universe — a fictional universe in which a series of games and books are set. ... Kiljaeden is a Supreme Demon Lord originated from the Twisting Nether in the fantasy Warcraft Universe. ...

Arthas came to his master's aid and killed Illidan in a duel. Due to the intense weakness of the Lich King's soul after the attack, Ner'zhul needed a new 'host' to live in. Arthas and Ner'zhul merged souls and became one entity - known as the Lich King.

Trivia

The name of Ner'zhul was misspelled as Ner'zuhl in some of the mission briefings (prologues) in Warcraft II: Beyond the Dark Portal.