契丹・宋間における外交文書としての牒

Abstract

Peaceful relations between the Khitan and Song dynasties were maintained for nearly 120 years following the conclusion of the Chanyuan Treaty in 1004. This study elucidates the framework that allowed the two states to remain at peace as equals over this lengthy period. It focuses on the means of communications employed by the two governments, and examines a specific type of diplomatic document in the use of the die, a document that was employed between offices or officials of equal rank, for direct negotiations between regional officials posted in the border area. After the first peace settlement between the Khitan and Song in 970 and prior to the treaty of Chanyuan, officials on the provincial level along the border conducted the diplomatic negotiations of the two states by exchanging letters on a personal basis. After the treaty of Chanyuan, a system was established in which regional offices above the provincial level in the border area exchanged die as diplomatic documents. In the Song dynasty, the procedure for drafting die differed depending on the significance of the matter involved. For minor matters a regional official was permitted to issue the document on his own, but in cases that were grave and required secrecy, the matter was always reported to the court in the emperor’s presence and the document drafted in response had to be issued under the direction of the court. Nevertheless, the Song concealed the existence of the directives of the court in response to the Khitan, and, by nominally placing the responsibility on the shoulders of the regional official who created the document, attempted to preserve flexibility in case negotiations did not proceed smoothly. Moreover, quoting the edicts of the emperor and the directives of the central government offices in the die made it possible for negotiations between both central governments to be carried out. This system of diplomatic documents established after the treaty of Chanyuan was carried on in eastern Eurasia by the Jin and Southern Song dynasties after the fall of the Khitan and Northern Song dynasties in the first half of the 12th century, and its influence extended into the period of the Mongol empire in the 13th century. There was no distinction in the form of documents used for domestic and diplomatic purposes during Chinese dynasties up through the Tang. This system of documents in written Chinese was adopted throughout eastern Eurasia after the demise of the Tang dynasty, but reflecting the international reality of many states, a clear distinction in the management of documents for domestic matters and those used in negotiations with other states arose. This may be judged to have been in fact the birth of the conception of diplomatic documents.