ABSTRACT
During the second half of the twentieth century only a few historians examined the available diplomatic documents, financial and administrative records and narrative sources systematically in order to gain a deeper understanding of the forms and methods of medieval diplomacy. As late as 1939 the doyen of traditionalist diplomatic theory, Harold Nicolson, emphasized that in the Middle Ages 'there was little opportunity for any orderly or established system of international contact'. Since the early 1990s, foreign policy and diplomacy have found renewed interest mainly among French and German medievalists. 'Diplomacy' will be taken to mean the peaceful conduct of external relations amongst rulers or ruling bodies and their representatives. They have, as parts of the terminology of modern politics, unambiguously secular and political connotations, which seem to render them unsuitable for the examination of a relationship between a spiritual and a temporal power in which legal and political issues were inextricably intertwined.
