On 24 June 2016, after months of public debate, it was confirmed that the people of the United Kingdom (UK) had voted by a narrow majority (51.9% to 48.1%) to leave the European Union (EU). The decision to leave seems likely to have a significant impact on the UK’s civil justice system and, in particular, on the rules of private international law applied to dispute resolution in a cross-border context. It is, however, a highly speculative exercise to predict the future shape of private international law in the UK in these circumstances. Putting speculation to one side, this article seeks to analyse legal events of the past to assess the position that the UK now finds itself in when approaching withdrawal negotiations. In particular, the following discussion seeks to identify the legal baseline of applicable private international law rules under international, EU and national law following withdrawal, with a particular emphasis on the domain currently occupied by the instruments applicable to civil and commercial matters (Brussels I, Lugano, Rome I, Rome II).