Dotaku are hanging bell-shaped bronze wares produced during the Yayoi period.
Dotaku are ritual utensils produced and used over about 400 years, between the second century B.C. and the second century. About 500 dotaku have ever been excavated all over Japan. The number of dotaku excavated in the main prefectures are shown as below (According to the research by the Agency for Cultural Affairs as of the end of March, 2001).
Hyogo Prefecture: 56
Shimane Prefecture: 54
Tokushima Prefecture: 42
Shiga Prefecture: 41
Wakayama Prefecture: 41
The size ranges from 12 centimeters to more than 1 meter. Around the first century, dotaku with 60 centimeters in height were started to be produced and, further getting bigger, they exceeded 1 meter in the second century and then finally reached 134 centimeters. Soon after this; however, the production of dotaku was stopped. The biggest in existence is 144 centimeters in height and 45 kilograms in weight (No. 1 dotaku excavated in Mt. Oiwa in Yasu Cho, Yasu City, Shiga Prefecture in 1881).
All dotaku produced in Kinki region have patterns on the surface. The most popular pattern is the Buddhist stole-like pattern, where lateral pattern lines and horizontal pattern lines cross each other. Before it, the running water-like pattern was popular. The oldest dotaku are decorated with the four-section Buddhist stole-like pattern with vertical pattern lines and horizontal pattern lines.
Also, they have a crown with a lozenge cross-section (lozenged crown type). However, small dotaku excavated in the Higashinara Ruins in Osaka Prefecture have a crown with a round cross-section. After the lozenge type, the crown shape underwent a transition: the outer-edged type, the flat type and then the raised-line type. And from later on dotaku itself grew in size with a decoration added on the surface.
Big dotaku exceeding 40 centimeters with the running water-type patterns appeared in the late second century B.C. This pattern declined in the first century B.C.
Some dotaku feature primitive paintings representing manners and customs of the Yayoi period such as houses.
Dotaku is said to have originated from Chinese copper bells but no similar shape has been found in Japan. In the Korean Peninsula, small bells without any letters and paintings, which are called Korean dotaku, have been discovered. Japanese dotaku can probably have been affected by these bells, but they developed individually after being brought to Japan.
Dotaku got bigger and bigger prominently from the end of the first century. These bigger dotaku have two types: the Kinki type and the Sanen type. It is thought that the Kinki type was produced in Yamato, Kawachi and Settsu Province while the Sanen type was made in the Nobi Plain. The Kinki type dotaku have been found mainly in the whole Kinki region, from Totomi Province in the east to the eastern half of Shikoku in the west and to Sanin region in the north, and the Sanen type ones are located mainly in the area from Shinano and Totomi Province in the east and the Nobi Plain in the west, and exceptionally in the eastern coast of Ise Bay, the eastern shore of Lake Biwa, and the coast of the Japan Sea in the northern part of Kyoto Prefecture. For both types, many were produced in the second century. In the end of the second century, only Kinki type dotaku were produced. After this, dotaku still got bigger but disappeared in the third century.
The record of discovery of dotaku can possibly track back to the description in "Fuso Ryakki" (A Brief History of Japan) saying it was found during the construction of Sofuku-ji Temple in Shiga District in Omi Province in the seventh year of Emperor Tenchi's reign. However, the details of this discovery were not described at all in both "Kojiki" (Record of Ancient Matters) and "Nihonshoki" (Chronicles of Japan), which should have included the detailed history in the Tenchi era. "Shoku Nihongi" (Chronicle of Japan Continued) says that a dotaku was found in Nagaokano by one from 宇波 Village in Yamato Province in 713 and "Nihon Kiryaku" (Outlines of the Annals of Japan) states a dotaku was excavated and called "Totaku of Ashoka the Great" in Harima Province in 821.
The purpose is uncertain at the moment but how they were used has been revealed to some extent from excavated states and marks on the surface. From the shape, it is thought that early small dotaku had a string or others hanging from a crown and a 'tongue (clapper)' made of wood, stone or a deer horn dangling inside the body through the top hole, and that it was rung when the tongue touches a raised-area on the inside wall of the body by swinging the body or the 'tongue' itself (same mechanism as in Western bells).
This can be guessed because some dotaku have marks of 'abrasion'on lower and side areas of the crown due to prolonged use for hanging a string, or marks of damage (dent) on the inside raised-area due to contact of the tongue, and therefore, a reproduced image of dotaku where they are rung by hitting the outer surface of the body like Buddhist temple bells is wrong because no such marks are found.
Since creating a rising, belt-like pattern inside a dotaku reduced the abrasion caused when it was rung, the use of two lines forming rising patterns became an increasingly common style as development of the dotaku continued.
At the end of the first century, when dotaku grew in size, the crown was changed to something more decorative and thinner, which possibly means the purpose was changed from "hearing" a sound to "exhibiting" them on the ground or floors of shrines (there is another theory described as below, though). This is called a transition from 'dotaku to hear' to'dotaku to see' (Taku TANAKA), and many of the latter one have ears (round or half-round ornament) on the edge of the crown and the fin (decorative plate along the body side). However, some have an additional inside raised-area (three-line type), which can be considered as a device for prolonged use for 'ringing' although they were not designed to ring a sound any more. This is probably an example that a decoration was extended to the inner surface, which was usually out of sight.
Status of burial
In most cases, dotaku were excavated at a foot of a hill or a bit lower area than the top of it outside of a village and found laid down sideways in a relatively shallow hole with several tens of centimeters in depth (there are two cases of upside down burying). Excavation of 1 or 2 dotaku from one site was common but there are five or six cases that 10 or more were concurrently found.
No excavation from the top of the hill is probably an important clue to revealing the purpose of dotaku and their religious status although this fact gets less attention. Also, unlike earthwares and stone tools, few dotaku were excavated from dwelling sites and, unlike other copper items such as doken (bronze swords) and dohoko (bronze pikes), no dotaku used as burial goods in tombs were discovered (One example exists of excavation at a groove surrounding the grave mound in the Yayoi period.), which indicates that dotaku were not private belongings but property of village communities.
And burial of dotaku took place intensively around the beginning of the first century and in the second century.
There are various theories about the reasons for the burial as below.
The first theory is to pray for good harvests of rice or other grains. But a counterargument says that if they were treasures for ritual purposes, they must have been treated in such a way but no marks indicating this are found. The question is, however, what the 'marks' specifically refer to.
The second theory says that they were normally buried and, on a ceremonial occasion, dug out and used, but later, less often used due to changes in the ceremonial or religious style, they were left for all in the ground (Seicho MATSUMOTO and others). Especially, unclearness of the patterns on the 'dotaku to hear,' which is thought to have been created due to a treatment such as polishing, not due to degradation over time in the ground from a burial through to an excavation, possibly shows that they were repeatedly dug out and polished every time a ceremony was held (Makoto SAHARA). It is said that in previous times in the southern east Asia area (Vietnam and others, but unknown now), bronze drums were usually buried and, picked up and used in the case of ceremonies and funerals.
The third theory is that they were dedicated to the god when a great happening occurred. However, the states of a burial need to be still considered: whether the case of discovering over ten dotaku from one site shows such many were buried in accordance with the scale of the 'great happening,' or whether the case of the concurrent burials all over the country show the 'great happening' occurred on a nationwide scale during the Yayoi period.
The fourth theory is that the bronze wares were customarily buried to appease ground spirits. Such custom was seen in the ancient South China.
The fifth is that dotaku were used as an appointment letter instead of mirrors in the times when characters were not established yet. However, it is doubtful in the first place whether such a powerful person or group as gave a mirror for an appointment letter existed in the Japanese islands at that time.
(In the Kofun period, there appeared to be not a few cases where alliance groups were given mirrors.)
Also, another critic says that this theory completely lacks a consideration regarding regional differences in the characteristics of dotaku, which probably deprived from differences of the cultural background each local producing group had.
The sixth is that people hid dotaku in the ground and escaped when a social change took place, such as attacks of a foreign enemy with a significantly different religious background from that of the Japanese island of that time, when dotaku were adored (Takehiko FURUTA). One theory additionally says that this 'foreign enemy' was possibly a descendant of the powerful group that later appeared in Japan. However, a counterargument says that if they had hid them in a hurry, various ways of burying would be found but the ways are similar all over the country. On the other hand, there is a theory that the hypothesis that the foreign enemy denied worship of dotaku and forced its local subordinates to abandon dotaku can explain the facts: that some dotaku were found broken, that worship of dotaku rapidly declined in the third century, and that the purpose have not been passed down at all.
The seventh theory says that dotaku were disposed of (in a lump if many existed) in the ground because they were not necessary any more due to political social changes (Kageharu MISHINA, Yukio KOBAYASHI and others). It means that when larger groups of people were organized by a new ruler that integrated individual villages of the Yayoi period, changes occurred in the ceremonial style from one of each community to one of a man with absolute power, leading to burial of dotaku that had been used in each village. In that case, it is thought that dotaku were broken in some villages, which can be the reason for excavations of broken dotaku. Also, the social and ceremonial changes here are often associated with a change to the next Kofun period.
However, it is dangerous to discuss all dotaku in a single uniform way because the purpose, the storage method and conditions of burial probably varied depending on the sites.
There is a theory that dotaku were made by recasting bronze wares imported from mainland China and the Korean Peninsula because a measurement of lead isotope ratio shows nearly same values between bronze wares presumably made in the early Yayoi period and those produced in the Yin (Shang) dynasty and Zhou (Western Zhou) dynasty and also because no bronze wares composed of such lead are seen in other areas or eras. In Japan, a historical record of copper first appeared in 708 (the first year of Wado, meaning "Japanese copper").
Dotaku cultural area and dohoko cultural area
Because ruins were less often excavated and neither were bronze wares before, there used to a biased distribution where dohoko were found mainly around northern Kyushu while dotaku were discovered in the area between Kinki and Tokai region. When this biased distribution was still predominant, the theory that the island from Chukyo to the west was divided into two parts, 'the dotaku cultural area' and 'the dohoko cultural area,' was not treated as a hypothesis and seriously discussed.
(There was even a theory that three cultural areas confronted, including Chugoku region as 'the doken cultural area.')
However, the more cases of excavation of bronze wares there were naturally along with increased excavations of ruins, the more situations where dohoko and doken were found in 'the dotaku cultural area' and where dotaku were discovered in 'the dohoko cultural area' (well-known example: the Yoshinogari Ruins) there were, which proved the hypothesis was not true as it was less and less often discussed.
However, a rough distribution of these wares has not been changed.
Dotaku and doka (bronze dagger-axe) of Sakuragaoka
National Treasure, excavated in Nada Ward, Kobe City, possessed by the Kobe City Museum
Batches of materials including 11 Buddhist stole-like pattern dotaku and 3 running water-like pattern dotaku
Among 14 dotaku, No. 4 and 5, on which sketches of men and animals were cast, are especially valuable materials.
Buddhist stole-like pattern dotaku
National Treasure, allegedly excavated in Kagawa Prefecture, possessed by the Tokyo National Museum
Similar sketches to those on Sakuragaoka dotaku were cast on this dotaku.
Articles of the Kojindani Ruins
National Treasure, excavated in Hikawa Cho, Hikawa County, Shimane Prefecture, possessed by the Agency for Cultural Affairs (maintained by the Shimane Museum of Ancient Izumo and others)
358 doken, 16 dohoko and 6 dotaku were excavated from a roof slope. They are academically valued in that dotaku mainly excavated in Kinai region, dohoko mainly excavated in northern Kyushu, and doken with a style unique to Izumo district were discovered in one site and also in large numbers. The dotaku are considered as the Japanese style's oldest dotaku.
Dotaku of Mt. Oiwa
Important Cultural Property, possessed by the Shiga Prefectural Azuchi Castle Archaeological Museum, the Tokyo National Museum, the Tatsu-uma Collection of Fine Arts, Yasushiritsu Rekishi Minzoku Shiryokan (the Yasu City History and Folklore Museum) (the Dotaku Museum) and others
In Mt. Oiwa in Koshinohara, Yasu City, Shiga Prefecture, 14 dotaku were excavated in 1881 and 10 dotaku in 1962. One of two possessed by the Tokyo National Museum is 135 centimeters in height, the biggest dotaku in Japan.
Dotaku of the Kamo-Iwakura Ruins
National Treasure, excavated in Unnan City, Shimane Prefecture (old Kamo Cho, Ohara County [Shimane Prefecture]), possessed by the Agency for Cultural Affairs (maintained by the Shimane Museum of Ancient Izumo)
39 dotaku, the most from one site in Japan, were discovered in 1996.
Raised-line running water-like pattern dotaku
Important Cultural Property, excavated in the Takatsuka Ruins in Okayama City, possessed by the Okayama Prefectural Museum
Raised-line Buddhist stole-like pattern dotaku
Important Cultural Property, excavated in the Yano Ruins in Tokushima City, possessed by the Tokushima Archaeological Museum