The Third War marks the global, multi-continental apocalypse that fundamentally shatters the old kingdoms of Azeroth. Unlike the previous wars fought against an invading @Orc armada, this conflict is orchestrated from the shadows by the demonic @Burning Legion utilizing a new, insidious weapon: the @Scourge. Imbued with the psychic malice of the imprisoned @Lich King, Ner'zhul, a virulent, magical plague of un-death is distributed through contaminated grain shipments across the northern @Human breadbaskets of Lordaeron, instantly killing the living and reanimating them as mindless, ravenous @Undead thralls.
The early stages of the war are defined by the tragic descent of Prince @Arthas Menethil. Desperate to halt the spread of the plague, the young @Paladinexecutes the ruthless, controversial Culling of Stratholme before pursuing the dreadlord Mal'Ganis to the frozen wastes of @Northrend. There, @Arthas Menethil takes up the cursed runeblade @Frostmourne, losing his mortal soul to the Lich King.
Returning to Lordaeron as a corrupted @Death Knight, @Arthas Menethil murders his father, King Terenas Menethil, and systematically decimates the northern Alliance:
Kingdom of Lordaeron: The capital city is turned into a slaughterhouse, and its farmlands are converted into the plagued, blighted Western and Eastern Plaguelands.
@Kingdom of Quel'Thalas: @Arthas Menethil marches upon the high elven kingdom, slaughtering Ranger-General @Sylvanas Windrunner and utilizing the mystical Sunwell to resurrect the archmage @Kel'Thuzad as an immortal Lich.
Dalaran: The @Scourge sacks the magical city-state, using the stolen spellbooks of Medivh to summon the demon lord Archimonde directly into Azeroth.
Guided by the cryptic prophecies of a mysterious Prophet (revealed to be the redeemed spirit of Medivh), a few desperate @Human survivors led by Lady @Jaina Proudmoore and a newly liberated @Orc Horde led by Warchief @Thrall flee across the Great Sea to the wild continent of @Kalimdor.
Upon arriving, they inadvertently breach the ancient, sacred territories of the isolationist @Kaldorei led by High Priestess @Tyrande Whisperwind and Archmage @Malfurion Stormrage.
Realizing that Archimonde and the @Burning Legion intend to drain the World Tree, Nordrassil, to consume the planet's life essence, the three bitter rivals forge a historic, unprecedented coalition at the base of Mount Hyjal. In a massive, multi-tiered defensive stand, the combined forces of @Humans, @Orc s, and @Night Elfs stall the demonic vanguard. The war reaches its ultimate climax when @Malfurion Stormrage blows the Horn of Cenarius, summoning thousands of ancient ancestral spirits who detonate around Archimonde, completely vaporizing the demon lord and burning the World Tree to break the Legion's invasion.
The Third War leaves Azeroth completely reshaped and geopolitically fractured. The ancient @Human and elven empires of the north are utterly eradicated, leading directly to the rise of @Sylvanas Windrunner's breakaway @Forsaken faction in the ruins of the Undercity.
Currently, as the mortal nations mobilize their armies to march into @Northrend, the entire global campaign against @Icecrown Citadel is viewed as the definitive, long-awaited final chapter of the Third War. The factions stand poised to deliver final judgment to @Arthas Menethil—the ultimate architect of the war's tragedies—completely unaware of what cosmic or terrestrial reckonings await them at the roof of the world.