The passport is one of the most widespread documents in worldwide use and yet, paradoxically, it has no basis in law: one state cannot demand another to do something give access - simply by issuing a document. Yet, by insisting on the requirement of holding a passport the state has provided itself with a neat self-financing, data collection and surveillance system. This is the story of the passport, from earliest times to the present day. When the Roman Empire was spread across Europe, those wishing to travel could only do so with the authority of the king or emperor. The passport's power to facilitate passage was, then, embodied in it from the beginning. But it is also connected with territorial and population control by the State. Today, the machine readable passport enables swift checks against lists of names, enabling customs control to sift out undesirables, and the question of identity cards (used throughout continental Europe) is again an issue in British politics. Using individual stories of the use of false passports and secret passage, and revealing the mechanism of the passport system, this book provides an accessible history of this most widespread of documents.