Britain’s vote on 23 June 2016 to leave the European Union came as a shock not only to many in the United Kingdom but also to many across the rest of the European Union. It was the first time that a member state had voted to withdraw from a Union that, since its emergence in the 1950s, had grown to encompass most of Europe and so become the continent’s predominant organization for economics, politics, social matters and non-traditional security (NATO remaining the key organization for defence). In the rush to analyse the meaning of the referendum result, the focus has been largely on the UK. Numerous studies and books have outlined the causes, consequences and meaning of Brexit for the UK. This book looks at the constituency it is leaving, and at how the rest of the EU has responded to Brexit. In particular, it analyses how the remaining 27 member states and EU institutions faced the UK’s attempted renegotiation of its membership terms, and its referendum campaign, and how they came to terms with the result and prepared for the formal Brexit negotiations triggered by Article 50, the section of the EU’s treaties that sets out how a member state can withdraw. It, therefore, covers the 21-month period from June 2015, when David Cameron informed the European Council that his newly elected government would seek a renegotiated relationship, through to March 2017, when Cameron’s successor as UK prime minister, Theresa May, informed Council president Donald Tusk that the UK was triggering Article 50. In reflecting on this period, the contributions also dwell on the history of UK–EU relations and give some hints as to how the rest of the EU has approached Brexit since March 2017.

The EU’s sheer size and diversity has meant that most analysis of the EU’s approach to Brexit to date has fallen back on offering a pan-EU view from Brussels, a focus on the big states such as Germany or France or a select sampling of certain member states, due to the consequences that Brexit holds for them – the most obvious case here being Ireland.