Brexit looms ever closer one of the many problem raised by the UKs departure from the EU is the British Overseas Territory of Gibraltar which shares a land border with Spain across which approximately 40 per cent of Gibraltars labour force cross daily. Real questions are being raised on the future of this border and how it will be managed but one can only understand its future based on a sound knowledge of its evolution. Barrier and Bridge explores the recent history of the border drawing on documentary and oral history accounts on both sides. It offers a human as much as a political history and argues that whereas at the beginning of the twentieth century there was virtually no border and strong cultural, economic, linguistic, and ethnic ties that straddled it, by the end of the century the border denoted a much more profound sense of difference between the populations. The book traces the complex developments over the twentieth century, looking at language change, marriage patterns, governance through the border, the Spanish Civil War and the Second World War and the changing relationship between the UK and the residents of the Rock who, over this period, identified increasingly as British. Eschewing a linear historical narrative, Barrier and Bridge explores the twists and turns, ambivalences and ambiguities, that inhere around this contentious border and concludes that we cannot expect its future to be as predictable as many would assume. Published in association with the Canada Blanch Centre for Contemporary Spanish Studies, LSE