The Defenders of Man Insurgency was a conflict that took place after the End War, between the Terran Dominion and the separatist group the Defenders of Man, who sought to undermine the rule of Emperor Valerian Mengsk. In an attempt to expose the weakness of the new regime, the Defenders of Man planted psi-emitters on Dominion worlds, moving to save them after showing the Dominion was too slow to provide any help.