After the events of the First Great War, Lord Lothar from the nation of Azeroth met with King Terenas of Lordaeron, together they united all the Human kingdoms with the Dwarven nation of Khaz Modan, the High Elves of Quel’Thalas, and the Gnomes of Gnomeregan in order to defend themselves against the Horde, which had destroyed the nation of Azeroth and left its people homeless.

The first Alliance.
All nations joined with conviction besides Alterac and Gilneas. Gilneas was one of the smallest nations at the time, but their King, Greymane, didn’t want to lose control of his own forces to the Alliance High Command and he felt that the nation could defend its own borders from impending invasion, as Lordaeron already effectively shielded it from Horde attack. However, he shortly afterwards hesitantly joined the Alliance out of necessity to ensure Gilneas’ survival, realising if the Alliance fell Gilneas would be unable to stand alone against the Horde and thrust its support into the war effort. The weakest nation, Alterac, little more than a city state high in the mountains of middle-Lordaeron, officially joined the Alliance but secretly had formed a partnership with the Horde, and started trading valuable tactical information with the warlocks of the Stormreaver Clan. The Alliance found out this duplicity after Alterac soldiers had started a riot in Tyr’s Hand and had attempted as assassinate the first paladin, Uther the Lightbringer. King Terenas was furious at this treachery and sent his forces to destroy the nation of Alterac. The city was razed, its lords stripped of their lands, and the populace dispersed. Today the city is in ruins and is currently occupied by Ogres, the nation of Alterac is no more.

The Alliance coat of arms — a combination of the racial crests of its members (the hammer, the eagles and the shield, the cog and the arrows representing dwarves, humans, gnomes and night elves respectively) — as seen in the World of Warcraft.However, after the events of the Third Great War, contact was made with the Night Elves from Kalimdor, who have joined the Alliance as well. Many of the surviving High Elves, their kingdom destroyed, had begun to use warlock magic because of the loss of their Sunwell. They became known as Blood Elves, and have joined the ranks of the Horde to sustain their need for a source of magical power. They have become a playable race for the Horde in the newest World of Warcraft expansion, The Burning Crusade. Although within the Warcraft lore, the total Alliance strength is considerably larger than the Horde, the Alliance is decentralized and without a strong leader such as Thrall; therefore, the effective strength of both sides is about the same.