Since the early twentieth century the resident embassy has been supposed to be living on borrowed time. By means of an exhaustive historical account of the contribution of the British Embassy in Turkey to Britain’s diplomatic relationship with that state, this book shows this to be false. Part A analyses the evolution of the embassy as a working unit up to the First World War: the buildings, diplomats, dragomans, consular network, and communications. Part B examines how, without any radical changes except in its communications, it successfully met the heavy demands made on it in the following century, for example by playing a key role in a multitude of bilateral negotiations and providing cover to secret agents and drugs liaison officers.