Second Great War: Swarm vs Dominion, 2504

The Second Great War was a conflict that broke out in 2504, four years after the Brood War, fought chiefly between the Zerg Swarm and the Terran Dominion. It ended in defeat for the Dominion and the death of Emperor Arcturus Mengsk at the hands of Sarah Kerrigan. Its most fateful consequence came midway through, when the deinfestation of Kerrigan allowed the resurrection of the fallen xel'naga Amon, setting the stage for the End War. (StarCraft II: Devils' Due; StarCraft II: Wings of Liberty; StarCraft II: Heart of the Swarm)

How long did the Second Great War last?#

The war broke out in 2504, when the Swarm struck Dominion worlds and the Raiders rose on Mar Sara, and it ran through the events of Heart of the Swarm to the Battle of Korhal, where Arcturus Mengsk died. Wings of Liberty and the timeline printed in Devils' Due agree on the 2504 start, but neither gives an exact date for the war's end, so any precise length in months is an estimate rather than something the sources state. (StarCraft II: Wings of Liberty; StarCraft II: Devils' Due; StarCraft II: Heart of the Swarm)

Background and the Four Years of Peace#

The Brood War had left Kerrigan and the reunited Swarm as the dominant power of the sector, and she granted the other powers a reprieve while sensing a greater threat on the horizon. The interbellum was spent in reconstruction. The Terran Dominion, again under Arcturus Mengsk, rebuilt and emerged as the preeminent terran power, while Raynor's Raiders made little headway against it. The protoss Daelaam struggled to integrate the Khalai and the Nerazim and slid back toward tribalism. (StarCraft: Brood War; The Story So Far)

Throughout these years the secret work begun by the agents of Amon, the creation of protoss and zerg hybrids needed for his vision, neared fruition. Zeratul, pursuing the Ulaan prophecy, learned that Amon's victory would mean the destruction of creation and that the one hope of averting it lay in Kerrigan's survival. Kerrigan, also seeking answers, resolved to fight the looming threat though she did not yet know its name. (StarCraft II: Wings of Liberty; StarCraft II: Heart of the Swarm)

The Artifact Hunt#

Two groups raced to gather alien artifacts. The Dominion enforced a ban on their trade, while Prince Valerian Mengsk secretly used the Moebius Foundation to assemble the pieces of a xel'naga device he believed could deinfest Kerrigan. Kerrigan, more aware of the greater conflict, ordered the Swarm to invade the sector and seize the device's pieces for herself as a weapon against Amon. Her preparations were detected by the Dominion, and four years of peace ended. (StarCraft II: Wings of Liberty)

Jim Raynor, leading a resurgent rebellion on Mar Sara, was hired through Moebius to recover the device's five scattered components, most of them guarded by the fanatical Tal'darim. Across battles on Monlyth, Xil, Tyrador VIII, Typhon, and a derelict xel'naga worldship, the Raiders gathered the pieces ahead of the Swarm. Valerian eventually revealed his hand to Raynor and offered an alliance to deinfest Kerrigan, an offer Raynor accepted over his crew's objections. (StarCraft II: Wings of Liberty)

The Battle of Char#

With the device complete, it had to be brought within range of Kerrigan on Char. Valerian requisitioned half the Dominion Fleet and placed General Horace Warfield in command. The frontal assault began in disaster, and only Raynor's initiative secured a foothold after Warfield's flagship was shot down. The terrans drove to the primary hive, emplaced the device, and held off the Swarm as its energy burst crippled the local zerg and returned Kerrigan to human form. (StarCraft II: Wings of Liberty)

Arcturus Mengsk had planned for this moment. The convict Tychus Findlay, freed in exchange for killing the Queen of Blades, fired on the helpless Kerrigan, but Raynor intercepted the bullet and killed Findlay. That Kerrigan survived Char was itself a divergence from the apocalyptic future the Overmind had once glimpsed. (StarCraft II: Wings of Liberty)

Flight, Rebirth, and the Swarm Resurgent#

Raynor and Valerian refused to surrender Kerrigan to Arcturus, and the survivors fled Char pursued by the Dominion Armada. At Space Station Prometheus they fell into a trap laid by Emil Narud, a servant of Amon, who escaped with the device. After Kerrigan was separated from Raynor and came to believe him dead from a Dominion broadcast, she set course for zerg space, intent on vengeance. (StarCraft II: Flashpoint; StarCraft II: Heart of the Swarm)

To reclaim and master the Swarm, Kerrigan gathered the broodmothers, recaptured Char from Zagara, and traveled to Zerus, the zerg homeworld. There the ancient primal zerg Zurvan guided her transformation in the first spawning pool, and she emerged reborn in a primal form free of Amon's corruption. At Skygeirr Station she learned from the infested Alexei Stukov of the Dominion hybrid program and destroyed Emil Narud, who told her with his dying words that Amon had already been revived. After rescuing Raynor from the prison ship Moros, the path to Korhal lay open. (StarCraft II: Heart of the Swarm)

The Battle of Korhal and Aftermath#

With Valerian's tacit approval, the Swarm descended on Korhal to depose his father. Kerrigan secured a landing zone outside Augustgrad, and the broods crippled the Dominion's orbital defenses. The Dominion deployed the Psi Destroyer, a weapon that turned the hive mind against the zerg, but the primal pack of Dehaka, immune to its effects, destroyed it. The Swarm laid siege to Korhal Palace, reinforced unexpectedly by Raynor's Raiders. (StarCraft II: Heart of the Swarm; StarCraft II: Legacy of the Void)

Kerrigan found Arcturus Mengsk waiting in his office above the xel'naga device that had once disabled her. When Mengsk turned it on her, Raynor destroyed the device, and Kerrigan exacted her vengeance, destroying Mengsk with psionic energy. With Mengsk dead, the Swarm withdrew, and Kerrigan departed to confront Amon. Valerian ascended to a Dominion in chaos, and with the Swarm gone from the sector the Daelaam under Artanis prepared to reclaim Aiur, a campaign that would coincide with Amon's return and the opening of the End War. Where this war falls between the Brood War and Amon's return is mapped on the StarCraft timeline. (StarCraft II: Heart of the Swarm; StarCraft II: Legacy of the Void)