The <i>Jori</i> Plan in Ancient and Medieval Japan

The process of the completion, change and breakdown of the jori plan and its function in ancient and medieval Japan are analyzed and explained comprehensively in this paper.<br> The jori plan was completed by the application of the jori indication system to the joyi grid pattern in the middle of the 8th century. It is thought that the completion of the jori plan was closely connected with new land laws in 723 and 743 which permitted private land ownership. The jori plan must have been effective for registry affairs which rapidly increased as a result of those laws. The jori plan was not imported directly from China with the Ritsuyyo system, nor did it exist as a completed system with the enforcement of the Handen-shuju.<br> We cannot find such a systematic and mechanical place indication system with ordinal numbers as the jori indication system in T'ang China. The jori plan was gradually completed and developed according to Japanese conditions in and after the 8th century.<br> The indication system of capital cities of Japan also developed in nearly the same way.<br> The jori plan was depicted clearly and used formally on Handen-zu which were the basic rural plans of ancient Japan. There must have been two types of such rural plans. One was drawn as a linear arrangement of ri, and the other depicted each ri separately. We can find 3 groups of representation method originating from both types.<br> The jori plan was still effective for bureaucratic procedures as the basic unit of formal permission and various rights or duties after the breakdown of the system of Handen-shuju in medieval times. Especially the function of the tsubo section was very active as the basic unit. Accordingly, the jori grid pattern has become a principal element of the traditional Japanese rural landscape.<br> The unit of ri was not so important as that of the tsubo, but sometimes the medieval estates or villages adopted the boundaries of ri as their own. The jori plan functioned till the 16th century in the regions where it was well-established, but we can find some errors on the maps due to the lack of information or necessity in medieval times.<br> The typical indication system progressively changed in accordance with completion, fixation and breakdown of the jori plan as follows: At first, an ancient place name was divided or revised to fit the jori grid pattern. Then the jori indication system was used with the ancient small place name. Before long the jori indication system was used independently. After that the small place name was used side by side with the jori indication system. Finally the small place name became to be used independently at the latest by the end of 16th century.<br> This stage is basically the same as the present method. Each stage of indication system cor-respond with each stage of social and economical condition of Japanese history. It indicates at the same time changing points or changing processes of the Japanese rural landscape. The joyi plan is a very important and effective key on the historical-geographical research of Japan.