This book provides the first comprehensive analysis of the withdrawal agreement concluded between the United Kingdom and the European Union to create the legal framework for Brexit. Building on a prior volume, it overviews the process of Brexit negotiations that took place between the UK and the EU from 2017 to 2019. It also examines the key provisions of the Brexit deal, including the protection of citizens’ rights, the Irish border, and the financial settlement. Moreover, the book assesses the governance provisions on transition, decision-making and adjudication, and the prospects for future EU–UK trade relations. Finally, it reflects on the longer-term challenges that the implementation of the 2016 Brexit referendum poses for the UK territorial system, for British–Irish relations, as well as for the future of the EU beyond Brexit.