<論説>北宋「滅び」への道程 --「二帝北狩」の成立-- (特集 : 滅び)

Abstract

北宋の「滅び」とは、靖康二年（一一二七）に金が都の開封を陥落させ、太上皇帝徽宗と皇帝欽宗を北方に連れ去った「靖康の変」で、もっぱら金の軍事力によってもたらされたと考えられている。しかし一度目に開封が攻囲されたとき、徽宗が開封にいなかったことを考えれば、二度目の攻囲で二人が同時に連れ去られたことは、決して当たり前のことではなかった。かかる事態に至るまでには、北宋ではじめて上皇となった徽宗と、皇帝欽宗との間に権力をめぐる争いがあり、結果欽宗が徽宗を屈服させて王朝の分裂を阻止し、徽宗を開封に呼び戻すという出来事があった。これにより欽宗が王朝の危機を回避していたからこそ、二人が同時に開封に存在することとなり、やがて同時に金に連れ去られてしまったのだった。つまり、「二帝北狩」の前提条件は、北宋自身の手でもたらされたものであり、「滅び」の一因を自ら調えてしまったことは、歴史の皮肉というべきものだった。

The “ruin” of the Northern Song is generally considered to have solely been the result of Jin military power with the fall of the Song capital Kaifeng to Jin forces in Jingkang 2 (1127) and the Jingkang Incident when retired Emperor Huizong and reigning Emperor Qinzong were forcibly taken to the north. However, Jin's attack on Kaifeng occurred twice, once in Jingkang 1 (1126) and again the next year. When Kaifeng was under siege and surrounded in the first year of the era, Huizong had abdicated to Qinzong and fled to Jiangbei and was not present in Kaifeng. Even if Kaifeng had fallen to the Jin at that time, if Huizong had resumed the throne, the Northern Song would likely have continued on. Likewise, in the same manner, if indeed Qinzong had explored leaving Kaifeng and withdrawn to the west, the Northern Song may have continued to survive in the west, even if Kaifeng had fallen. This would have been precisely like situation of the Tang dynasty at the time of An-Shi rebellion, where the fall of the capital city did not mean the fall of the dynasty. Considering this fact, the two Jin attacks and the capture and removal of both Huizong and Qinzong cannot be taken as matters of course. Why were Huizong and Qinzong in the capital when the Jin attacked Kaifeng for the second time? Qinzong finally never withdrew to the west. This was due to his following of Li Gang's firm advice; he chose to remain in the city and rely on its strong walls. This policy resulted in triumph, and the fall of Kaifeng was averted. However, at the same time this led to the conclusion of a peace treaty with the Jin whose conditions were overwhelmingly disadvantageous, revealing just how much Qinzong feared a direct attack on the capital. On the other hand, Huizong and his close advisors were in Jiangbei, whence he issued orders written in his own hand, sequestering supplies and strengthening his forces. This action appeared to be the direct opposite of Qinzong's policy of defending the capital to the death, and because previous studies have seen Huizong's behavior as invariably self-serving, his return to the capital has been taken as a given. However, this situation was the first case in the Northern Song of there being an emperor and retired emperor at one time, and there was a dispute over which held the greater power. It was not possible for the emperor's side to exercise legitimate power from the start. In other words, in some cases the retired emperor held great power, similar to the rule of retired emperors in Japan. One can recognize widening behind-the-scenes struggle between the two sides of the split in imperial authority. As a result, because local officials followed the orders of Qinzong and ceased to cooperate with Huizong, the impoverished Huizong in dire straits was forced to consider returning to Kaifeng. On the other hand, because Huizong's party was militarily powerful, if Qinzong were to miscalculate in his response, there was fear that fighting might erupt between them. Thus, with extreme care, Qinzong encouraged Huizong's return, and placating Huizong's close advisor Cai You, somehow succeeded in persuading him to return. As a result of this, the Song dynasty avoided a split. However, precisely because the dynasty was able to avoid this danger, Huizong and Qinzong were both in Kaifeng at the same time, and when the Jin attacked, they were captured and taken away. In other words, the prerequisite for the “northern captivity of the two emperors” was brought about by the Northern Song dynasty itself, preparing its own “ruin, ” which could be called one of the ironies of history.