This chapter critically reexamines the Oromo military campaigns of the 16th and early 17th centuries, shifting the analytical lens from external colonial and ecclesiastical narratives to an indigenous Oromo historiographical and structural explanation. Demmeksa argues that the successes of the Oromo were not due to sheer numbers or migratory luck—as posited by figures like Abba Bahrey—but stemmed from an internally sophisticated and morally grounded civilizational system anchored in the Gadaa democratic order. The chapter identifies eleven interrelated factors contributing to Oromo military, social, and political success: the Gadaa system (rotational governance), age-set institutions (Cibra), the unifying goal of reclaiming ancestral land (Galma), spiritual conviction (Kaawoo), guerrilla warfare (Gaaduu), logistics and food innovation (Galaa), and inclusive sociopolitical integration (Moggaasaa), among others. Special attention is given to how decentralised command, moral economy (Safuu), ecological intelligence, and the sacred commitment to national restoration empowered Oromo warriors to defeat both Christian and Islamic imperial forces. Demmeksa also reevaluates Abyssinian sources, revealing how fear, admiration, and religiously motivated propaganda shaped the portrayal of Oromo campaigns. Ultimately, the chapter restores Oromo strategic agency and reframes these campaigns as an organised national liberation movement, rather than as demographic coincidence or a pastoralist incursion.