The present paper has as its main theme the attempt of trying to define the concept of Britishness, both from its national and imperial perspective, and to analyze its complex relationship to such issues as ethnicity and culture, especially in the post-war period, when Great Britain is faced both with the collapse of its empire and with massive immigration from its former colonies and dominions. The analysis will be both a synchronic and a diachronic one, with an important focus being placed on the shift of national consciousness from one epoch to the other, always trying to offer the historical backdrop for these evolutions as well. Also, the paper will stop and analyze some major issues that brought about mutations in the national imaginary, like for example colonial discoveries and the appearance of the stereotype of the savage, the American Revolution and its implications, the Irish problem, and the processes of devolution and multicultural acceptance that marked the last decade of British politics. We will thus try to understand the causes that lead to the current crisis in national identity and try to analyze the possible solutions to this complex problem.