Combining corpus linguistics, critical discourse analysis, and a discourse analysis of narratives, this book considers one aspect of the Brexit process: the language that journalists, politicians and individuals used to write and talk about what it means to be British and European around the time of Brexit. It reveals a trajectory towards a discourse of national division in Brexit Britain in three datasets: pro-Brexit newspaper articles, UK Government documents, and interviews with individual citizens.Demonstrating the important role that (supra-)national identity discourses played in discussions about Brexit, the book traces a shift towards a representation of Brexit Britain as divided and in decline at a time when the construction of a collective identity is likely to be paramount. The emerging representation is a direct contradiction of the great global trading nation narrative that the Vote Leave campaigners - and later the UK Government - promised, questioning the discursive success of the Global Britain project.Constructing Brexit Britain demonstrates that the transition from pre- to post-Brexit Britain was a crucial period of destabilisation for institutional and lay national identity narratives. It also illustrates that the coming years are likely to be just as important, as the UK forges its post-Brexit place in the world amid declining levels of trust in politicians, calls for a second Scottish membership referendum, the COVID-19 pandemic, and a cost of living crisis.