The Chinese document “Wei-shu” written in the 3rd century A.D. recorded that the Japanese people (known as “Wa” people at the time) iron was actively sought the metal, along with the Han and the Ye peoples. used as a medium of exchange, like money in China.
Iron is thought to have been the most important item traded in Yayoi times. With the introduction of rice farming technology which came first, followed a little later by the importation of bronze and iron implements, the Yayoi period was an age of technological revolution.
By the late Yayoi phase, iron had replaced stone as the choice material for tools as far as Tohoku district in northern Honshu island. Iron minerals were easier to find in large quantities than bronze and because sharp tool edges could be made with it, iron was used for more practical things like tools and weapons. Bronze was rarer than iron and which produced a duller edge, but being more malleable, nearly always tended to be reserved for making ceremonial objects and prestige goods.
The earliest excavated metal specimen was a flat iron axe made of high-grade forged steel from the Magarita site in Fukuoka prefecture (dated to the Initial Yayoi period) and the Saitoyama site (Early Yayoi period) also in Fukuoka prefecture.
Iron tools excavated from the Yayoi period include:
- point planes;
- reaping knives;
- needles; and
Among the first imports from mainland Asia were the large bi-facially beveled stone axes used for harvesting lumber. Other new items introduced from the peninsula: stone reaping knives, wooden rakes for preparing fields, farming spade and hoe, polished stone daggers and arrowheads (along with cylindrical beads and the raised granary warehouse) were previously unknown in the Japanese islands.
Although the immigrants came with the knowledge of metallurgy techniques, metals were too scarce to be used as farming tools, so stone was still used with occasional iron tips for the tools. Quadrangular stone axes and flat plano-convex stone adze heads were used to make wooden farming implements, pestles and mortars, following the earlier Jomon tradition of stone tool-kits.
By the end of the Yayoi period, nearly all stone tools had become extinct, a sign that they had been replaced by iron. Iron was a valuable material however, and was constantly recycled and remelted down for making new tools over the years. Hence, very few iron artefacts have been recovered from archaeological digs.
Metal was a durable material especially useful for making tools for agriculture and warfare. Iron tools with sharp cutting edges could be produced making the work of reaping harvests, clearing forest undergrowth and cutting lumber more efficient.
The introduction of metalworking produced one important improvement in Japanese daily life that we take for granted today. Iron needles were less clumsy than the Jomon bone and stone needles of yesteryear. Now, the privileged social classes could enjoy woven garments of silk and hemp that could be sewn together in more complicated fashions. Most common people, however, continued to wear the rougher textured and simpler clothes made of ramie … often merely woven cloth with a hole for the neck and tied with a sash at the waist.
The above important metal technological innovations impacted society and changed the way of life rapidly on the Japanese islands. The control of the supply of iron or bronze resources created a special and elite status for those who controlled the resources.
The need for Korean iron also set in motion a process of inter-regional conflict and local consolidation of central power that was to characterize the following Kofun Period as ruling “kings” of the Kinai region expanded their bases of power westward along the Inland Sea and northern Kyushu as well as made shifting political alliances with different kingdoms in the Korean peninsula.
Where did the iron come from?
The earliest iron foundry to be discovered is in the Yangtze area of China. In May of 2003 archeologists found the first relics of an iron casting workshop along the Yangtze River, dating back to the Eastern Zhou Dynasty (770 BC-256 BC) and the Qin Dynasty (221 -207 BC).
Because the 3rd century Chinese document “Wei-shu” reports that iron resources were found in southern Korea, iron technology and the supply of iron were once thought to have to have come to Japan from the Korean peninsula alone which had begun iron production under the influence of the Yen culture of the Chinese Warring States and possibly also under Siberian influences from the Tuman River Basin.
The role of the Korean peninsula at the time as a source of iron is recorded in the Chinese histories such as Sanguo ji:
“Pyonhan produces iron. Han, Ye and Ancient Japan [Wa] all come to buy it. Iron is used for buying and selling and Pyonhan also supplies iron to the two Chinese commanderies of Lelang and Daifang.”
According to Korean scholars, “At the time, the Japanese did not possess the skills to produce iron and thus imported iron from Korea’s southern regions to make iron implements. Among the Samhan states, Guya (present-day Gimhae) was the center of iron production. According to the articles on Byeonhan in the Book of Wei of the Records of the Three Kingdoms, Guya sold iron to the rest of Samhan, as well as to Dongye, Nangnang and the Japanese states, and that iron was also used as currency.”
Many iron objects, both weapons and tools, from the tombs of this period have been discovered but experts find it difficult to tell whether they are Chinese or Korean products. The Chinese records suggest that iron technology was introduced from China into Korea through the establishment of Chinese commanderies in the north of the Korean peninsula. And until recently, most experts believed that ironworking in East Asia was introduced via that route at least before the 4th century BC since full-scale usage of ironware was seen in China. Chinese iron technology was already advanced by this time — China’s oldest excavated iron foundries on the Yangtze River date to the 7th century B.C.
Some scholars, on the other hand, believe that development of iron technology was indigenous — since it happened at the same time both in the north and south of Korea before the establishment of the commanderies, beginning around the time of the founding of the Chosun state. The Han Chinese had attacked Chosun as part of its expansionist policy and in its search for more sources of salt and iron.
Archaeologists have recently discovered another source of Korean ironworking technology apart from the Chinese one. Russian archaeologists as well, have maintained that iron technology came into central Asia at a relatively early time, when the inhabitants began to use ironware without first passing through the Bronze Age. Recent events have clarified the history of iron technology:
In 2007, 2000 artifacts were excavated from the Barabash-3 settlement site, including earthen vessels and nine iron artifacts, such as an ax and an arrowhead. (Barabash village is 70km away from the border between Korea and Russia in a direction of Vladivostok.)
Among those artifacts, the excavated ironware is made of gray cast iron, which predates the Chinese ironwork by 2 to 3 centuries. Scholars of the history of iron technology had previously believed that cast iron first appeared in China as gray iron. (Gray iron, which is made by adding graphite, requires more sophisticated technology than white iron.) This technology first appeared during the 2nd century BC in China and had spread all over the country by the 1st century BC.
Archaeologists have recently finished excavating at Barabash an iron manufacturing workshop from sometime between the 7th and 5th centuries BC. Nearby the prehistoric iron manufacturing site, artifacts from the Bohai(or Parhae) culture related to those in the Korean peninsula were discovered in two places. The experts found when examining the iron relics, that stone axes had already been replaced by iron axes at this period. Archaeologists also uncovered a crescent-shaped stone knife (半月形石刀; 반월형석도), a relic that marks the rice-growing culture on Korean peninsula. There were signs at recently excavated site that the workers destroyed on purpose their iron manufacturing workshop when they migrated elsewhere.
While Chinese records stated that Japan bought iron from Pyonhan in southern Korea, it is now believed that iron and iron technology of early Japan may also have been of Chinese provenance and some, possibly Siberian (Central Asian) provenance.
Most early Yayoi* iron artefacts, were Chinese-style foundry-made iron were probably items of Chinese trade. A large number of wrought-iron plates, were very similar to those mass-produced by the Han iron industry (see above), have been found in Japan and are said to be imports from China. Several early iron axeheads from Kyushu closely resembling early Chinese cast-iron implement-caps are also said to have Chinese provenance. Two iron-production sites excavated in Kyushu, including the find of one of the earliest bloomeries found in East Asia, suggest a Siberian provenance for the technology.
Excavations have shown extensive trade of iron in various forms between Japan and the mainland. The great demand for iron and the need for access to iron sources from Yayoi times has been a determining factor in many of the key political and military events in Japan during the Kofun and Yamato years.
* Note: Most sources cite Initial Yayoi or Early Yayoi dates for the influx of the earliest iron into Japan, however, the National Institute for Cultural Properties in Nara’s Shoda Shinya states that both the early 1st millenium BC dates of the northern part of the Korean Peninsula as well as the Japanese Early Yayoi Period chronologies are unreliable and need to be set back to younger dates, the latter to the Middle Yayoi period. Shoda is of the view that only the AMS C14-based dates in South Korean sites are sound.
Archaeologist Charles T. Keally explains the radiocarbon dating controversy differently and backs the radiocarbon ages of the Yayoi artefacts:
“In Japan, the oldest generally accepted evidence of iron use comes from the Magarita site in Fukuoka Prefecture (Hayamaru Yayoi 2003). This iron was found with Yuusu I pottery of the Earliest Yayoi period, giving it a simple radiocarbon age of about 700 BC or older (see Harunari et al. 2003). This date is 200-300 years older than the 4th-5th century BC that archaeologists give for the beginning of Yayoi. Even the dates available before 2003 (Watanabe 1966; Keally & Muto 1982; Imamura 2001) suggest that this site is older than 500 BC and most likely 600 BC. These simple radiocarbon dates become about 750-800 cal BC in calibrated years (see Stuiver et al. 1998).
There are several other sites yielding iron artifacts that date from the beginning of Early Yayoi, for example, the Saitoyama Shellmound in Kumamoto Prefecture (Wajima 1967, pp. 435-436), the Imagawa site in Fukuoka Prefecture (Saiko no tetsu 1980), and the Okamoto Yonchome site in Fukuoka Prefecture (Nihon saiko no tekken 1980).
There even are two Latest Jomon sites claimed to have evidence of metal use in Japan before the Yayoi Period began. Cutting and stabbing marks on human bones from the Itoku site in Kochi Prefecture were identified as those made by a metal implement (Jomon-jin no hone 2002; Kizu ato jinkotsu 2003). These bones were associated with middle to late Latest Jomon pottery, thought to date to around 2800-2500 BC [uncalibrated radiocarbon date]. The newpapers, however, reported the radiocarbon date [calibrated?] of this site as about 3200 BP, or about 1260-1130 BC [cal BC?] (Kizu ato jinkotsu 2003).
There also is the completely overlooked terminal Latest Jomon site in Kushiro City, Hokkaido, that yielded a fragment of an iron artifact in a burial (Kono 1973). Available dates (Watanabe 1966; Keally & Muto 1982) suggest this iron dates to at least 500 BC (ca. 750 cal BC) and possibly 600 BC (ca. 800 cal BC) (see Stuiver et al. 1998).”
Sources of iron and bronze technology on the continent; Iron smelting technology in China likely diffused from Scythian nomads in Central Asia around 8th century B.C.; Earliest source of Korean ironworking technology may have been Russian (Jankowski Heritage of Japan
Bad science and the distortion of history: Radiocarbon dating in Japanese archaeology by Charles T. Keally, Sophia International Review, February 4, 2004
last revised: May 14, 2004
A History of Japan (The Blackwell History of the World), Conrad Totman
The Cambridge History of Japan: Ancient Japan ed. by John Whitney Hall
Prehistoric Japan: New perspectives on insular East Asia by Keiji Inamura
An Article on the Excavated Bronze and Iron Artefacts from Ancient Tombs of Korea by Kim Gwong-gu, Keimyeung University Museum
The use of white cast iron in ancient Korea by Jang-Sik Park and Mark E. Hall iams, 25,2005,9-13
Iron in Ancient China, The Jade Road website