A study of political changes in the Kofun period, on specific standards of construction of keyhole-shaped tomb mounds

探讨了古坟前期至中期大型锁眼墓丘的具体建造标准，并给出了其过渡序列。特别是从樱井-秋山古fun开始的过渡系列表明大和王朝有几个权力。我们对川町地区的玉山古坟群的土地进行了研究，并对泉和哈里马地区的锁眼形墓丘进行了大地测量。建立全国锁眼墓葬数据库，并开展数字化建设。这些研究结果表明，继位的国王会更新自己陵墓的标准，与国王有政治关系的地方酋长会建造与国王陵墓相似的陵墓。也就是说，古坟标准的过渡系列体现了大和王朝与地方权力之间的政治关系。此外，对类似墓葬的澄清可以指出与国王相应的具体地方权力。在川町地区，拥有锁眼状墓葬的有效地方权力随着从乌山古坟集团到崎古坟集团和古坟集团的过渡而发生变化。Izumi和Harima地区也是如此。我们的结论是大和王朝在古坟前期到中期并没有建立一个政治政权。我们还估计发生了两次政治变化，一次在早期结束，另一次在古坟时期中期开始。

We discuss specific standards of construction of large keyhole-shaped tomb mounds and provide their transition series from the early to the middle of Kofun period. Especially the transition series started with Sakurai-Chausuyama Kofun indicate that Yamato dynasty had several powers.We conduct research on the land of the Tamateyama kofun group in the Kawachi area, and geodetic surveying of keyhole-shaped tomb mounds in the Izumi and Harima area. Databases of keyhole-shaped tomb mounds across the country are made up and their digitalization is also developed.Results obtained from these researches show that a successive king updates the standard of his own tomb and local chiefs politically related with the king construct similar tombs with the king's tomb. That is, transition series of Kofun standards demonstrate political relations between Yamato dynasty and local powers. Moreover, clarification of similar tombs is able to point out the specific local power corresponding to the king. In the Kawachi area, effective local powers with keyhole-shaped tombs change over in conjunction with transition from the Oo-yamato Kofun group to the Saki Kofun group, and to the Furuichi Kofun group. The same holds in the Izumi and the Harima area. We conclude that Yamato dynasty does not establish one political power from the early to the middle of Kofun period. Also we estimate that two political changes are occurred, one in the end of the early and the other in the beginning of the middle of Kofun period.