This textbook provides a comprehensive introduction to the strategic history of the past two centuries, showing how those 200 years were shaped and reshaped extensively by war. The book takes a broad view of what was relevant to the causes, courses and consequences of conflict. The volume provides students with a strong grounding in the contribution of war to the development of the modern world, from the pre-industrial era to the age of international terrorism and smart weapons. Covering all the major wars of the past two centuries, the third edition has been revised and updated and now includes: new introductory essays at the start of each section to help students recognize historical turning points and strategic themes; revised and updated material on the post-Cold War period, accommodating new developments and contemporary perspectives; new material on non-Western views on strategy, especially Sun Tzu; a new chapter on ‘The age of acceleration and great power competition’, starting with the death of Bin Laden and ending with the Ukraine crisis; a new Conclusion offering a synthesis between the message of earlier editions and the state of strategy today. This textbook will be essential reading for students of strategic studies, security studies, war studies, International Relations and international history.