On the General Maps of Japan compiled by the Tokugawa Shogunate

Abstract

The purpose of this paper is twofold: one, to correct a misunderstanding about the Keicho Nihonzu, one of the Nihonsozu, or general maps of Japan, housed in the National Diet Library, and two, to compare and contrast compilation methods and contents of such Nihonsozu, which were compiled by the Tokugawa Shogunate during the Edo Era.Until now, it has been thought that the Nihonsozu were produced at four times, during the Keicho, Shoho, Genroku and Kyoho periods of the Edo Era, although the production of the Keicho map has been mere conjecture. It has been assumed to have been produced on the basis of a Kuniezu, or provincial map, compiled as a result of a 1605 government order. There is no record, however, to support this production. It is known that the existing Keicho Nihonzu was probably produced in the Kanei Period (1624-1643), however as a result of lack of knowledge of the compilation of Nihonsozu during the Kanei Period, it has been assumed to be an amended version of the original Keicho Nihonzu. The present work supplies evidence that the Nihonzu known as the Keicho Nihonzu and housed in the National Diet Library, is in fact the Kanei Nihonzu, and was produced by Masashige Inoue, a government officer, in the 16th year of Kanei (1639).Comparison of the four Edo Nihonzu (Kanei Shoho, Genroku and Kyoho) reveals the following: 1) Since Nihonsozu were always compiled on the basis of Kuniezu, their accuracy depended upon how well the Kuniezu were compiled. 2) This method of extending the Kuniezu reached its practical limits during the Genroku Period. Thereafter, for the Kyoho Period, a new method, depending upon a rudimentary survey, was initiated. 3) The later maps are not necessarily more detailed, though they reflect the political state of affairs at the time of their production. 4) Drawing of the northern boundary islands, Ezochi (Hokkaido, Kuriles and Sakhalin) does not progress in detail over the four periods. Howewer the southern boundary Ryukyu Islands (Okinawa Prefecture) become more detailed and more accurate in the Genroku Nihonzu.