This article analyses the Howard League's campaigning against the death penalty in mid-20th-century British colonies. It examines two case studies: the Howard League's campaign to limit the death penalty in the Palestine Mandate in the 1930s and their silence on mass executions during the Kenya Emergency in the 1950s.Drawing on Ben-Natan's (2021) concept of the dual penal regime, we argue the Howard League concentrated its intervention in ordinary penal regimes and demarcated emergency penal regimes as outside its sphere of interest and influence. Consequently, it was silent on the penal excess of colonial authorities during periods of counterinsurgency. Criminology as a discipline largely shares this demarcation of the penal measures associated with colonial wars, militarism and states of emergency as beyond its purview. Inclusion of these aspects of colonial penality into the criminological narrative highlights the significance of colonialism and colonial ways of thinking to penal liberalism.