In recent years, the Schengen Area—and the suppression within its territory of border controls—has become a strong focus of attention. This article focuses on another region of Europe where such controls have been suppressed: the Common Travel Area (‘CTA’). Historically, both Ireland and the United Kingdom have rejected membership of the Schengen system—albeit securing certain ‘opt-in’ rights—and instead maintained the CTA between their respective jurisdictions. The CTA has, however, garnered relatively little public attention until recently, when concerns as to the implications of Brexit for the maintenance of an open border between Ireland and Northern Ireland have gained ground, and threatened to be a deal breaker in the negotiations under Article 50 TEU on UK exit from the EU (‘Brexit’). This article examines the background to the CTA, exploring its surprisingly fluid legal framework; its development in the legal systems of Ireland and the United Kingdom; and subsequently, how it was exempted from what is now EU law as the Schengen arrangements were integrated into the Union. The recent introduction of the British-Irish Visa Scheme, which formalises some visa rules regarding citizens of third states, and which tends in the direction of consolidating CTA arrangements, is also examined. The article further explores the challenges that confront the CTA in coping with the outcome of the June 2016 Brexit referendum, which should result in the UK leaving the European Union in March 2019, and the implications of Brexit for the CTA. Finally, it seeks to identify some key characteristics of the CTA in light of experience to date.