Half a decade after the referendum, and reams of publications later, this special issue of Global Policy takes a step back from the heated and relentless maelstrom of events. Its authors set out to consider Brexit from a wider diachronic perspective, in order to examine not only its complicated present, but also its past and possible future(s). To this end, the special issue's three sections contain four articles each, plus a special spotlight on the Irish border and the Ireland/Northern Ireland Protocol. Experts in history, law, political and social science gauge the ideational factors and historical pathways that prepared the way for Brexit; discuss the significance of some of the legal, formal and constitutional features of the process; and indicate probable consequences going forward. They aim to do justice to the idiosyncrasies of the UK’s exit from the EU and to draw out its wider repercussions and significance.