Kurume History Walks
Ontsuka

No.10

G o n g e n zuka K o f u n

Ontsuka and Gongenzuka Kofun 御塚・権現塚古墳

Kofun is the ancient mounded tomb of people in power, constructed between about the mid-3rd century tothe early 7th century (the Kofun period).
The "Ontsuka and Gongenzuka Kofun", which are in fact two separate tombs, was designated a National
Historic Site in 1931. The Ontsuka Kofun is a keyhole-shaped mound (zenpokoefun), while the Gongenzuka
Kofun is a round mound (enpun).
We presume those kofuns were the tombs of Minuma no Kimi (a powerful family of Mizuma District during
the Kofun period). They were mentioned in an ancient book which was edited in 720.

Tombs of chieftains
Those kofuns are located in Daizenji, at a lowland between the Chikugo River and the Hirokawa River. It issaid that there used to be over 40 tombs in the neighborhood.
There are still several small round tombs, less than 20 meters across. A certain kofun as large as theGongenzuka seems to have been demolished to develop new arable lands.
In a wider area, six keyhole-shaped kofuns exist. Considering these scales, we regard them and three above
kofuns together as the tombs of Minuma no Kimi.

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21 Ontsuka and Gongentsuka Kofun
2 Daizenji Tamatare-gu Shrine

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

Overview
We investigated both kofuns twice at the same time.
The Ontsuka is keyhole-shaped (scallop-like), surrounded withtriple moats and embankments, 121 meters in overall length. The
main part had been robbed of its buried properties.
The Gongenzuka is round, 152 meters across, surrounded bydouble moats and embankments, while we suppose it had anotherperipheral, shallow groove. A lot of properties such as Silla* wares
and cylindrical clay figures (ento haniwa) were buried in the innerembankment. They were probably set up under a plan.
As for the creation date of the kofun, we estimated, from theexcavated articles, that the former was built in the late 5th century
Excavated clay figures

and the latter was in the early 6th century.
*Silla was one of three kingdoms on the Korean Peninsula from the 1st century BCE tothe 7th century.

Minuma no Kimi, a powerful clan
The former Mizuma District, which takes part of Kurume City

today, was an important area as the gateway to the Ariake Sea.

Silla wares

Several large kofuns stud along the river. If we consider all as the tombs of Minuma no Kami, recorded in“The Chronicles of Japan (Nihon Shoki)”, it should be them who dominated this important area and the river
traffic.
By the way, in the late 5th century, Chikushi no Kimi clan had the biggest power in the northern Kyushu.
They had a significant influence on the kofun culture of this province. The clan prospered in the generation ofTosu City

TANUSHIMARUOTSUKA KOFUN
Ukiha CitySHIMOBABA
KOFUN
Kurume City

GONGENZUKA
KOFUN

ONTSUKA
KOFUN
IWATOYAMA
KOFUN
Yame City

Major kofuns along the Chikugo River

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Kurume History Walks / No.10 Ontsuka and Gongenzuka Kofun

Iwai. The Iwatoyama Kofun, located in Yame City, is considered as his tomb and as one of the largest kofuns inKyushu by the early 6th century. And, because there are several kofuns around the Iwatoyama Kofun, it is likelythat Chikushi no Kimi clan kept their home ground on the Yame Hills.
Iwai rebelled against the Yamato Kingdom in 527. He lost the battle at the foot of Mt. Kora according to“Nihon Shoki”.
The biggest reason why the Yamato Kingdom aimed for conquering Kyushu was to monopolize thenegotiation right with China and Korea. From historical materials of the Munakata-taisha Shrine, anotherpowerful clan, Munakata no Kimi clan, controlled a sea route from the Genkai sea to the Korean Peninsula andthe continent. There should have been an alternative route from the Ariake Sea, and if it is so, the home groundof Minuma no Kimi along the Chikugo River could have been the contact point with the continent. They had
been closely connected to the Yamato Kingdom as early as Munakata no Kimi.

Investigation by a samurai,
Yano Kazusada
Yano Kazusada, a samurai of

Kurume Domain of the end of the Edo
period, was born to the Hayakawa
family in 1794 at the castle town. At theage of 34, he entered the Yano family inorder to succeed the family work as thehorse guard of the lord. After that, heheld various posts such as teacher of
Meizendo domain school, promotor of
the study of Japanese classical literature,high-ranking promotor of new growing
industriescreation.

Kazusada

hadThe Ontsuka (lower left) and Gongentsuka (upper right) Kofun

poured energy to research the local
culture and wrote a lot of books invarious fields. Especially War Historyof Generals and Forces of Chikugo
Province (Chikugo Shoushi Gundan,1853) still has a high use value as a
general history book.
In this book, he also wrote about
Ontsuka and Gongenzuka Kofun andthe survey value by the field research.
He depicted those mostly as those aretoday. And his measured value was very
close to the result of our investigation.

Draft of “Chikugo Shoushi Gun Dan”

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Restoration work
In 1913 and 1917, the field surveyof the Ontsuka Kofun was carried out by
Kuroiwa Manjiro and Muto Naoharu
from the Chikugo history club (ChikugoShidankai), Masuda Ushin, the chief of
the Archives and Mausolea section of theImperial Household Agency and others.
They estimated that that was a tomb of
Minuma no Kimi.
Fukagawa Tadayoshi, the presidentof the Okawa Railway Company, thought

During the restoration workthat it was a shame to keep the kofun witha long history in disrepair. Then, he spent
private funds to buy the land of thekofuns and its neighborhood – 30,000
squaremeters,andrequested

therestoration to Kajita Sadaichi, who was incharge of the restoration of the Imperialmausoleums across the country. It seems
that he had used the survey drawing ofYano Kazusada.
The photos on the right show that

After the work

the restoration was on a large scale. The local volunteers took part of the work. After that, Tadayoshi asked thelocal people to maintain clean all the land that he bought.

Recent circumstances
After the World WarⅡ, the land around the kofuns changed into a housing land for repatriates from thecontinent. They refilled those moats, cut the embankments and flattened it. In 1958, there used to be 25 houseson that land.
In 1970, the city undertook the environmental improvement around the Kofun in earnest in order to use
effectively it. It purchased private lands from the citizens for enlarging the preservation zone. In 1979, the areaof 50,000 square meters was finally added to the designated site.
Since 1985, the improvement work had carried out. In 1994, the restoration of both kofuns was completed
and a public square was opened. The restoration had been done referring to the measured value by Kazusada in
1917. The kofuns might have regained the form at the time of the Edo period.
Cultural Properties Protection Department of Kurume
Address: 15-3 Jonan Kurume Fukuoka Japan 830-8520 / Tel: 0942-30-9225
Date of revision: March 31st, 2015 / Translated in June 20204Kurume History Walks / No.10 Ontsuka and Gongenzuka Kofun