Shakushain's War stands out as a watershed event in the history of the conquest of Ezo. Shakushain exploded onto the scene as a charismatic leader who proved able to bridge regional differences among Ainu communities, threatening to unite them against the Japanese intrusion from the south. The Tokugawa shogunate reacted by solidifying its own united front of military allies in the northeast, replacing local Matsumae generals with men of its own choosing, thus illustrating its self-appointed role as defender of the realm.