This updated and enhanced second edition of History and International Relations charts the foundations, development and use of International Relations from a historian's perspective. Exploring its engagement with the history of war, peace and foreign relations this volume provides an account of international relations from both western and non-western perspectives, its historical evolution and its contemporary practice. Examining the origin of dominant IR theories, exploring key moments in the history of war and peace that shaped the discipline, and analysing the Eurocentric nature of current theory and practice, Malchow provides a full account of the relationship between history and IR from the ancient world to modern times. To bring it up to the present day and provide new ways for students to grasp the history of IR, this new edition includes:-An updated final chapter reflecting on the practice of IR in a post 9/11 world -New scholarship and sources in IR practice and theory published since 2015-A time line charting the evolution of International Relations as a discipline -A new glossary of terms -Expanded section on IR theory and practice in the ancient world and early Christian era -Greater incorporation of IR practice and theory in non-western ancient, medieval and modern worldsHistory and International Relations is essential reading for anyone looking to understand international relations, diplomacy and times of war and peace in a historical context.