This study offers a comparison of the military roles played by commissars, political officers and chaplains in military settings ranging from the armies of Cromwell, the Jacobins, the Nazis, the Soviets and the USA. Despite the stark differences in the political systems of the countries of these disparate armed forces, the author argues that there are certain critical functions that must be fulfilled in every military, regardless of its ideological orientation. Most vital are motivation, morale boosting and political socialization.