An absorbing new history of European colonialism, showing how ideas of retribution and revenge were used to justify violent conquest and rule. Today, the use of military force to punish enemies is strictly prohibited under international law. It is also a widely accepted principle that acts of vengeance and reprisal have almost no legitimate place in warfare. Throughout much of Western history, however, punishment and retaliation were not only important aspects of conflict, but were key justifications for waging war in the first place—particularly when it came to the defence of national honour. European empires were no exception to this rule. Throughout the nineteenth and early twentieth centuries, two of the world’s most formidable powers, France and Britain, regularly framed wars of conquest and counterinsurgency using the language of justice and revenge. Whether to avenge alleged insults, punish perceived transgressions, or exact retribution for ‘crimes’ committed against the dignity and authority of Europeans, ‘honour’ was used as a legal, religious and moral rationale for violent expansion, consolidation and policing. Based on extensive archival research in multiple languages, Empire with a Vengeance is the first comparative examination of honour and revenge in colonial policy. Showing the central importance of these seemingly archaic concepts, it offers crucial insight into the brutal dynamics of empire’s ‘civilising mission’.