This article offers a textual and historical reconstruction of Francis Bacon's thought on imperial and colonial warfare. Bacon holds that conquest, acquisition of peoples and territory through force, followed by subjugation, confers a legal right and title. Imperial expansion is justified both by arguments concerning the interstate balance of power and by arguments related to internal order and stability. On Bacon's view, a successful state must be expansionist, for two key reasons: first, as long as its rivals are expansionist, a state must keep up and even try to outpace them, and, second, a surplus population will foment civil war unless this “surcharge of people” is farmed out to colonies. These arguments for imperial state expansion are held to justify both internal and external colonization and empire. Paradoxically, Bacon holds that the internally colonized may be treated with greater severity, as suppressed rebels, than the externally colonized, who are more fitly a subject of the ius gentium. Bacon holds that toleration offers both an imperial stratagem and a comparative justification for why English and British imperial expansion is more desirable than Spanish imperial expansion. The article concludes with reflections about how one might understand the place of imperial and colonial projects in Bacon's thought, contending that these projects are central to an understanding of Bacon's political aims and thought more broadly.