ABSTRACT
The custom by which one state might send an individual to represent its interests in another state is one of the oldest practices in international society. In an age devoid of telegraph or telephone communications, a representative was the most practical option for the ruler who wished to communicate with a ruler of another state. It is not a matter of coincidence that some of the earliest writers on international law had served in some form of diplomatic capacity. Indeed, after the study of international law passed from the theologians in the 16th century many of the writers on international law had some direct experience of diplomatic service. In the broadest terms a diplomat is a person who represents his state in another state and is concerned with political relations between the two states. The powers and immunities of such persons grew up steadily as a result of state practice in the 17th and 18th centuries and were well understood by the time of the Congress of Vienna in 1815. The first permanent legations date from the 13th century and by 1500 England, France, Spain and Germany kept permanent representatives at each other’s courts. The role of the permanent legation increased under Cardinal Richelieu not least because of the opportunities it provided for the gathering of information. Originally, the language of diplomacy was Latin but by the time of Louis XIV diplomatic affairs were regularly conducted in French. By 1919 English was employed on an equal footing with French; the emphasis on language is of some consequence because treaties tended to be drafted in the language used by the diplomats.
