In the disciplines of political science and international relations, Machiavelli is unanimously considered to be “the first modern realist.” This essay argues that the idea of a realist tradition going from the Renaissance to postwar realism founders when one considers the disrepute of Machiavelli among early international relations theorists. It suggests that the transformation of Machiavelli into a realist thinker took place subsequently, when new historical scholarship, informed by strategic and political considerations related to the transformation of the US into a global power, generated a new picture of the Renaissance. Focusing on the work of Felix Gilbert, and in particular hisMachiavelli and Guicciardini, the essay shows how this new interpretation of Machiavelli was shaped by the crisis of the 1930s, the emergence of security studies, and the philanthropic sponsorship of international relations theory.