The UK has generally leaned towards intergovernmental rather than supranational relations despite the significant restrictions on their sovereignty that 47 years of EU membership have entailed. These supranational constraints were not only a cause behind their attempt precisely to ‘take back control’ but have also been especially present during the process of Britain’s withdrawal from the Union. Thus, this book brings together the many valuable lessons the British have left us with concerning the legal and procedural constraints that are placed on an EU Member State’s withdrawal and which have also led to a post-Brexit Britain that continues bound by important supranational features that have crossed over from their abandoned membership into their new relationship with the EU.