Although the three modern periods of internment in the United Kingdom remain relatively unexplored in the migration literature, these historical episodes have significantly impacted the development of that country’s immigration policy, law, and legislation. This paper seeks to explore the outcomes of these internments and to draw connections between them and the development of the contemporary immigration detention estate. As such, it presents a historical overview of the First World War, Second World War, and Gulf War internments in the UK. These findings illuminate how powers granted to the UK government on an emergency basis became normalised and repackaged as everyday tools of contemporary immigration enforcement. The working paper also demonstrates how a liberal state government utilises atmospheres of fear, distrust, and xenophobia to justify depriving foreigners of their core individual rights in the name of national security concerns.