At the beginning of the twenty-first century, when Ireland and Britain are ‘offshore islands’ of an ostensibly ever-deepening European Union, it is, perhaps, relatively easy to overlook that imperial stage upon which both Irish partition in 1920 and the Anglo-Irish settlement of 1921 were enacted. Yet without this wider context, these momentous decisions are impossible to understand fully. Current questions about whether Ireland has essentially been a colony will inevitably continue to be debated, but the imperial circumstances of these events remain inescapable and essential to a full appreciation of the mindset of the leading participants in these affairs.