This module surveys the main theories in the academic discipline of International Relations (IR). It adopts a quasi-chronological approach, beginning with the philosophical roots of IR theories and ending with contemporary theoretical debates. Attention will be paid throughout to the historical and social context from which theoretical developments emerged, and how these are relevant or useful in our understanding of contemporary security issues. The aim is to equip students with the necessary conceptual and analytical tools that can then be applied to their own specific areas of interest or field of research. By the end of the module students should be able to understand the key theoretical debates in the subject of IR.