Although Jesuit contributions to the European expansion in the early modern period have attracted considerable scholarly interest, the legacy of José de Acosta (1540-1600) is still defined by his contributions to natural history. The Theologian and the Empire presents a new biography of Acosta, focused on his participation in colonial and imperial politics. The most important Jesuit active in the Americas in the sixteenth century, Acosta was fundamentally a political operator. His actions on both sides of the Atlantic were instrumental in the configuration that Peruvian colonial life and the Jesuit order acquired entering the seventeenth century.