The Third War marks a decisive turning point in the history of Azeroth, characterized by the convergence of multiple global crises that reshaped political structures, populations, and the balance of power. Unlike the earlier conflicts between the orcish Horde and the human kingdoms, this war was defined by the emergence of existential threats that transcended factional boundaries, most notably the Scourge and the demonic Burning Legion. Its course unfolded across Lordaeron, Kalimdor, and the Eastern Kingdoms, culminating in the destruction of established realms and the formation of new alliances.
The immediate prelude to the Third War lay in the spread of the Scourge in northern Lordaeron. This undead plague, introduced through cursed grain distributed among human populations, led to mass death and reanimation. The crisis destabilized the Kingdom of Lordaeron and overwhelmed existing political and military institutions. Efforts to contain the plague failed, in part due to fragmented authority and conflicting responses among regional leaders.
The transformation of Prince Arthas Menethil into a death knight and his subsequent assassination of King Terenas II effectively ended Lordaeron as a functioning kingdom. Arthas’s actions facilitated the rapid expansion of the Scourge and opened the way for the return of the Burning Legion, whose invasion strategy relied on weakening mortal civilizations from within. While the exact degree of autonomy exercised by Arthas during this period is debated, most accounts agree that his campaign was instrumental in preparing Azeroth for demonic incursion.
Following the fall of the capital city, the Scourge overran much of northern Lordaeron, including key population centers and religious institutions. The Silver Hand, once the primary military and spiritual defense of humanity, fragmented under the strain. Some of its members were slain and raised as undead, while others fled south or went into exile.
The neighboring elven kingdom of Quel’Thalas was drawn into the conflict when the Scourge invaded its territory to seize arcane resources. The destruction of the Sunwell resulted in the near-annihilation of the high elven population and permanently altered their society. Survivors later redefined themselves as blood elves, marking a profound cultural and political shift whose long-term consequences extended well beyond the war itself.
Concurrently, developments in the south altered the global balance. The orcish Horde, under new leadership, abandoned its internment camps and undertook a mass migration to Kalimdor, motivated by both spiritual visions and strategic necessity. Human survivors from Lordaeron, led by remnants of the Alliance, also crossed the sea in pursuit of safety and answers regarding the spreading demonic threat.
On Kalimdor, these groups encountered the night elves, whose ancient civilization had long guarded the continent against demonic return. Initial encounters between humans, orcs, and night elves were marked by mistrust and armed conflict, exacerbated by cultural differences and incomplete knowledge of the broader threat. Over time, the scale of the Legion’s invasion forced reluctant cooperation among these factions.
The war thus differed fundamentally from earlier conflicts: traditional enemies found themselves aligned against a common foe, while older political divisions temporarily gave way to pragmatic military cooperation.
The Burning Legion’s return constituted the central axis of the Third War. Its strategy combined demonic armies, corrupted mortal agents, and the Scourge as an advance force. Major battles occurred across Kalimdor, particularly in regions of strategic and symbolic importance tied to ancient magical sites.
The Legion sought to access powerful sources of arcane energy and to dismantle the natural and spiritual defenses of the world. Resistance efforts focused on delaying tactics, evacuation of civilian populations, and the consolidation of disparate forces into a unified defense. The night elves played a critical role in coordinating this resistance, drawing upon their long historical memory of previous Legion invasions.
The climax of the Third War occurred at Mount Hyjal, where the combined forces of humans, orcs, and night elves confronted the Legion directly. This battle represented both a military and ideological turning point. Sacrificial strategies were employed to exploit the Legion’s reliance on overwhelming force and corruption, ultimately resulting in the defeat of its primary commanders present on Azeroth.
The destruction of key demonic leadership did not eradicate the Legion entirely, but it ended its immediate invasion and shattered its operational foothold on the world. The cost was immense: vast territories were devastated, ancient forests destroyed, and countless lives lost. The night elves, in particular, suffered irreversible changes, including the loss of their immortality, which marked the end of an entire epoch in their history.
By the end of Year 21, the Third War had effectively concluded, though hostilities and instability persisted in many regions. The Scourge remained active in the north, and no single political power emerged capable of restoring pre-war order. Instead, the conflict ushered in an era defined by fragmentation, reconstruction, and ideological realignment.
The Third War is generally regarded as the end of the classical age of the human kingdoms and the beginning of a new geopolitical landscape. Its legacy shaped all subsequent developments in Azeroth, influencing factional identities, territorial control, and the perception of existential threats beyond conventional warfare.