The zone of international administration of Tangier represented one of the last examples of a particular form of internationalised control over strategically and couuuercially important territories. The city and hinterland of Tangier came to form a separate administrative entity within a broader series of international treaties which brought Morocco under French and Spanish protection in 1912. This thesis examines the origins and evolution of the diplomatic negotiations which led to the signature of the Statute of Tangier of 1923, its constitutional basis and its implementation over the twelve years for which it was initially valid. The main argument of the thesis is that as a compromise agreement designed to satisfy the diplomatic and commercial interests of the main signatories of the Statute (France, Spain and Great Britain), the practical application of the Statute was not assured of success. As an international instrument it failed to satisfy the theoretical assumptions underlying similar "internationalised" agreements in assuring equal access to the benefits and control of the zone it created. As a constitutional arrangement, it attributed more rights to those powers - and especially France - which enjoyed a prior claim to influence over Morocco. As an example of international law, it encapsulated an often contradictory respect for the sovereignty and integrity of the territories of the Sultan of Morocco with the demands of practical governance and European international relations. Within the first decade of its application, the Statute nevertheless proved to be a durable and flexible instrument. Through the evolution of pragmatic, and often locally-inspired, solutions to problems of interpretation and balance, the first officials of the international administration set the foundations for a régime which endured, in modified forms, until the independence of Morocco in 1956. The precedents established in the period 1923-1935 served not only to define specific relationships between the institutions created by the Statute. They also determined the autonomy of Tangier relative to the other zones of Morocco, thanks largely to the defence by individual officials of the interests of the Tangier zone.