Britain's unruly North American colonists broke away from the British Crown and established the United States of America almost two hundred and fifty years ago. The subsequent relationship between Britain and its former colonies, whose new state developed over time into the most powerful state in the world, has always been complex, at times a source of conflict, at others of cooperation. A variety of terms have been used to describe this relationship. They include the Anglo-world, the English-speaking world, Anglo-America and most recently the Anglosphere.

Anglo-America is the broadest term, denoting for example that part of America that feels a particular empathy to things British, a relationship between particular states, a transnational political space, a political myth, and a political project. The Anglosphere is a very good instance of the last of these. Anglo-America is, however, more than a political project, it is an ‘imagined community’, encompassing both ideals and interests, which is constructed and sustained through various narratives and embodied in particular institutions. Such transnational political spaces are a key feature of our world, although less studied than either nation-states or the global economy. Such spaces arise particularly around the great powers of each era, but they exist to some extent for all states, since no state is entirely self-contained. Some states because of their history are involved in many such transnational spaces, some of them overlapping. For Britain the three most important have been the Empire, Europe, and Anglo-America. Such spaces and the communities of interest and ideals to which they give rise can be a potent source of political identity and political projects.