Byzantine diplomacy

Byzantine diplomacy concerns the principles, methods, mechanisms, ideals, and techniques that the Byzantine Empire espoused and used in order to negotiate with other states and to promote the goals of its foreign policy. Dimitri Obolensky asserts that the preservation of civilization in Southern Europe was due to the skill and resourcefulness of Byzantine diplomacy, which remains one of Byzantium's lasting contributions to the history of Europe and the Middle East.[1]

Olga, ruler of the Kievan Rus', along with her escort in Constantinople (Madrid Skylitzes, Biblioteca Nacional de España, Madrid)
Modern depiction of the reception of the ambassadors of Emperor Constans II at the court of Tang Taizong at Chang'an, 643 CE