It is therefore common to label Byzantine diplomacy as “war by other means” (Antonucci, 1993: 11). They were unique in their method of involvement in internal affairs of other countries For this aim, the empire initiated a new institution for diplomatic practice, the Bureau of Barbarians, responsible for the imperial post, the supervision of diplomatic officers, and the reception of foreign envoys; and he eventually became the emperor’s chief adviser on foreign affairs. The logothete was also responsible for the internal security of the empire until the 11th century. The Bureau sent envoys on diplomatic missions to barbarian lands in order to gather information from every possible source. This was the main function of it. After the envoy’s return to Byzantium, which took mostly years, the information they had reported were recorded and constituted the essential basis of their knowledge on the weaknesses or strengths of their enemies and/or allies.