太上天皇制の成立

抄録

It is important to clarify the Tenno system in the ancient Japan. Under the system, not only Tenno but also Dajotenno could have the right of the the sovereign. In China, there were T'ai-shang-huang and T'ai-shang-huang-ti in the capacity of Dajotenno in Japan. But there was much difference between the system in Japan and the one in China. In China, under the principle that the nation should have the only one sovereign, it was natural that the abdicated emperor should be a subject of the new emperor. But in the case of the abdication in one dynasty, the abdicated emperor was not a subject of the new emperor. The abdicated emperor called himself "T'ai-shang-huang" when he handed over the sovereignty to the new emperor. And he called "T'ai-shang-huang-ti" when he did not. In Japan, the abdicated Tenno could be one of the two sovereigns by prescribing the Dajotenno system under the ritsuryo codes. As a result, the abdication under this system was to produce another sovereign. The reason why this system was established though it was in definite in some sense was that Japan had to overcome many difficulties in order to develop into the ritsuryo regime. In that time, Japan required the stability of the regime, for Japan must check some troubles concerning the succession to the throne which often occurred during the seventh century. The Dajotenno system was effective to check them. Under the ritsuryo regime, "Tenno" (as the sovereign) was to, having the original political power, deside both important national policies and miscellaneous everyday affairs. "Tenno" was requested to have the ability to dicide all of them. Dajotenno and Tenno reigned over the bureaucracy, and both attended some functions which both had better attend and either of them attended others which either might attend. This condition was suitable for Japan in that time. This Dajotenno system lost its substance when Japan had been perfectly under the ritsuryo regime and its indefinite rule caused some troubles concerning the sovereignty.