Pax Romana is often seen as an aggressive force, imposing the will of Rome on her empire. Perhaps it is because of this that Roman authors are often seen as having a dismissive view of peace and an admiration, if not a love, of war. The only literary area where this has been questioned at any length is in verse, most fully by the elegists. This thesis, therefore, focuses on the concept of peace in the philosophy and historiography of late republican and early imperial Rome, drawing examples from classical Greece and early Christian texts when necessary. The first section acts as an introduction to the possibility of a more positive attitude to peace by examining the most striking negative presentations of war: just war theory and civil wars. The second section examines the main philosophical schools from the period and argues that the Stoics, Cynics and Epicureans share pacifistic views that are not merely utopian but are grounded in important tenets of their respective philosophies: oikeiosis, cosmopolitanism, and the unimportance of material and physical virtues for the Stoics and Cynics; divine self-sufficiency, the avoidance of pain, and the importance of friendship for the Epicureans. Some even willingly reject more traditionally Roman values, like gloria, because they conflicted with the philosophical antipathy to warfare. An examination of the usages of the terms pax and concordia in the historians of the time argues that the dominant view, that they were suspicious of peace, is not wholly accurate. Sallust and Livy provide numerous examples that suggest a more open attitude to peace and, at times, even seem to share some of the pacifistic beliefs of the philosophers. Further, even the more militaristic historians can present peace as a state preferable to war.