Monograph No. 17
NARA IMPERIAL PALACE ARCHAEOLOGICAL SURVEYS CARRIED OUT DURING 1961--1963（1966）
ENGLISH SUMMARY
CONTENTS
Page
Chapter I. Introduction 1
Chapter II. Progress of Research Work 4
1. General Description of Research Work 4
2. Daily Record of Excavation Work and Events 6
Chapter III. Sites 9
1. General Description of Excavated Area 9
2. Architectural and Structural Remains 10
Chapter IV. Artifacts 19
1. Wooden Writing Tablets 19
2. Roof Tiles and Bricks 20
3. Pottery and Sherds 23
4. Wooden and Metal Objects 33
Chapter V. Studies 38
1. Sites 38
2. Artifacts 51
3. Wooden Writing Tablets and Government Offices and Bureaus 55
4. Conclusion 62
TABLES
Page
1. List of Excavated Architectural Remains in Area 6ABO 67
2. Classification of Round Roof-edge Tiles 68
3. Classification of Curved Roof-edge Tiles 70
English Summary x
NARA IMPERIAL PALACE
EXCAVATIONS AT THE HEIJO PALACE SITE: RESEARCH REPORT IV
In the summer of 1955, members of the staff of the Nara National Research Institute of Cultural Properties began excavations at the site of the Heijo Palace compound, where the imperial domicile, halls of state, and other important administrative buildings were located during the Nara Period (710-784). Work at this extensive site, which lies west of the present-day city of Nara in an area covered largely by rice fields, has continued over the following years, producing an impressive number of relics and much valuable information. As a result of this research, a clearer, more accurate picture of the culture which flourished in the capital during the eighth century has emerged.
The present report deals chiefly with recent excavation work in plot 6ABO, and represents a continuation of the investigation and study on this area which was dealt with initially in the Research Report on the Heijo Palace Site, volume II, which appeared in 1962. With the publication of the present volume, survey work in this area may be regarded as tentatively complete. Area 6ABO is situated roughly in the center of the northern section of the palace compound, and extends approximately two hundred and twenty meters from east to west and ninety meters from north to south. The remains lay preserved at various levels, superimposed one above the other, and extended throughout the entire area. For this reason, the horizontal system of excavation was employed in order to carry out the investigations in the most thorough manner possible. The methodical application of this exhaustive method over such an extensive area of land marks a new stage of development in archaeological research in Japan.
The excavations revealed that there have been five successive stages of building activity in the vicinity, four dating to Nara times, and one carried out later, at the beginning of the Heian Period. It seems probable that the first (lowest) stage represents the remains of the earliest period of construction when the palace compound was initially erected shortly after the capital was established at Heijo in 710, although the evidence is too meagre to draw any conclusions about what sort of structures stood on the site at this time. During the second stage, which seems to date to about the end of the Tempyo period (729-749), there was a government bureau located in the area, and it is presumed that it was occupied by the section in charge of the Imperial Household cuisine, which appears to have remained in this area during stages three and four also. During the third stage (which falls into the Tempyo-hoji period, 757-764) government office buildings stood in the eastern part of this area, while the western portion seems to have contained storage structures. During this period the land in this vicinity appears to have been divided off into broad divisions designed for rather specific architectural purposes, but in the extensive rebuilding which occurred toward the end of the Nara period (stage four) the systematic overall layout characteristic of the government of fice buildings and storage structures in this area during stage three was abandoned, and replaced by various independent groups of buildings. These groups of structures were also used by government sections or bureaus, and were utilized for such specialized purposes as the manufacture of soy-sauce or confectionaries, or the preparation and service of foods. This fact explains their division and layout according to individual blocks. Whether this change in plan represents a development confined only to this area, or is a feature common throughout all the official bureaus and office buildings in the palace compound, is a challenging problem which must be taken up during future excavation and research at such locations. The last period of construction (stage five) may be assigned chronologically to the early years of the ninth century when the palace of the retired emperor Heizei was located in the compound. It remains unclear, however, just what buildings stood in the area under discussion at that time, or how they were disposed. Another question that will have to be clarified by future research is the location of the Imperial Household bureau in charge of cuisine during the early part of the Nara period, from the initial erection of the palace compound until the last part of the Tempyo period (pre-stage two).
In the majority of cases, the structures that housed government offices or bureaus were constructed with their pillars inserted simply into the ground, rather than set up on exposed foundation stones. Now, although the numerous buildings still preserved from Nara times in temple compounds have led scholars to a general agreement that the chief architecture of the eighth century was strongly Chinese in style, characterized by raised stone foundations and tiled roofs, the excavations treated here have revealed that this conclusion must be revised, and the role and importance of this variant style in which the pillars are set directly into the ground, must be reappraised. Another significant difference in these structures were the roofs, which were probably covered by either wooden boards or materials such as bark, for tiles were apparently not used. Buildings of this sort were ideal for being erected simultaneously in large numbers, since their dimensions and construction features were standardized, a fact which is demonstrated by the many remains from such structures unearthed at Area 6ABO. An unfortunate feature of this type of architecture, however, was its limited period of durability, and none of the structures seem to have lasted for long, principally because of the direct contact of the bases of the pillars with the earth. It is natural, therefore, that periodic rebuilding was necessary, and this seems to have been one of the important influencing factors in the four successive stages of construction carried out at the site during the Nara period.
The most valuable finds among the relics recovered at the site are a group of thin, flat wooden tablets which bear writing. These were discovered among other fragments in a pit and in a well, locations where they had been discarded. The evidence provided by these articles has clarified a number of points about the nature of the remains, the government bureaus that stood in the vicinity during Nara times, and their chronology. Furthermore, their existence has made it clear that tablets of this sort were widely used for clerical purposes during Nara times. The inscriptions are of particular importance ‐ one, for instance, which is written on a baggage docket originally attached to tribute articles, has substantially clarified our knowledge of the actual circumstances of the Nara period tax system.
Roof tiles, intact as well as in fragments, together with various earthenwares and sherds, have come to light in considerable numbers at the site. Careful study of these objects has revealed that they passed through a gradual series of stylistic and technical changes over the period of roughly a century when palace compounds were situated in the area, from the time of the establishment of the capital at Heijo until the period of residence at the location by the Emperor Heizei after his retirement. As a result of the close, regular pattern of development that has emerged, it has been possible to reconstruct the sequences of stylistic change on a firm basis, and this has provided the evidence necessary for the establishment of an absolute chronology for the tiles and pottery of the period. With continued research, it is thought that the individual stages in this stylistic development can be accurately narrowed clown to twenty year periods.
Prior to the excavations in Area 6ABO, the area was covered by level rice paddy fields, and there were no indications that ancient remains of any sort were preserved in the vicinity. As a result of the investigations at this location, however, the foundations of many structures used for government offices or bureaus (kanga), laid out on an extensive scale, were uncovered, the first evidence of the existence of such buildings at the Heijo site. Because of the importance of these finds, it was decided in 1963 to purchase the entire area originally enclosed in the Heijo Palace compound (about 100 hectares) with government funds, so that it could be carefully preserved and its contents studied, a plan which has recieved wide approval in scholarly circles.
Now that the area has been acquired by the government, it has finally become possible to initiate a thoroughgoing investigation of the entire expanse of ground according to a careful, well-coordinated program of excavations. With the knowledge gained from this work, it is certain that many pages of Japan's ancient history can be rewritten and expanded with greater accuracy and insight in the future.
昭和41年2月20日 発行
奈良国立文化財研究所学報 第17冊
平城宮発掘調査報告 Ⅳ
- 官衙地域の調査2 -
