<論説>渤海の交通路と五京

Abstract

渤海の出京の位置に関して、説の分かれている中京顕徳府・西京鴨[リョク]府は、『遼史』地理志の検討から中京は顕州に置かれ、吉林省和竜県西古城に、西京は同省臨江県に比定した。五京が置かれた意義に関して、その役割の一つが対外交通の拠点であったことを指摘した。特に唐との交通は重視されたが、二本あるルートのうち西寄りのそれが奚・契丹によってしばしば塞がれたため、東寄りの鴨緑江を経由するルートの比重が高まり、それが鴨[リョク]府に西京の名が付される要因となった。また、鴨緑江沿いでは従来の政治的中心地である集安ではなく臨江に西京が置かれたのは、その水路と陸路の転換点という地理的条件のためであり、臨江は唐との交易ルートの拠点として重視された。このような交易ルートの拠点としての役割は東京龍原府にも見ることができる。

It is confirmed by examining the geographical section in the Liaoshi (遼史地理志) that Zhongjing Xiandefu中京顕徳府was located in the site of Xigucheng 西古城 of Helong 和龍 Prefecture of Jiling Province, the place named Xianzhou 顕州 at the time, and Xijing Yalufu 西京鴨淥府 in Linjiang 臨江 Prefecture of the same Province. One of the functions of five capitals was to serve as bases in foreign areas. Bohai regarded its relations with the Tang 唐 dynasty as most important, and there were two routes between Bohai and the Tang dynasty. But the western route of the two was often obscured by the Qidan 契丹 and Xi 奚 nations, so the eastern route, by way of the Yalu River (鴨緑江), became more important. This is why the name Xijing, western capital, was added to Yalufu. Along the Yalu River, Xijing was located not in Ji-an 集安, the political center before that time, but in Linjiang owing to the fact that it was the junction of a land route and a water route and regarded as an important base along the trading route with the Tang dynasty. It can also be said that Dongjing Longyuanfu 東京龍原府 functioned as a base along the trading route. Thus, as to the functions of the five capitals, we must consider not only their political but also their economical functions.