Fuhonsen coin (富本銭)
Fuhonsen coin or Futosen coin are coins made in Japan around 683. It is older than Wado-kaichin issued in 708, therefore it is considered as the oldest coin in Japan. There are different theories as to whether the coin was actually distributed or just used for incantation.
It was a round coin with a rectangle hole; the round shape of the coin had a diameter of 24.44 mm on an average, and had a square hole 6 mm on a side (to be exact, rectangle 0.5 mm longer on a long side) in the center. The thickness was around 1.5 mm and the weight was from 4.25 g to 4.59 g. It was modeled after Kaigen-tsuho issued in 621 in Tang. On the surface it was marked '富夲' vertically and shichiyosho pattern (seven star pattern) in Kikko (hexagonal pattern) horizontally. The character '夲' is considered as a variant character of '本' (hon). Mostly the material was copper including antimony. It was used intentionally to decrease the dissolution temperature for easier casting and to increase the strength of the product. Also a slight amount of silver and bismuth was included. The word 'Fuhon' is derived from a historical event 'food and money are the source to enrich people' of "Tokankanki" from encyclopedia "Geimon-ruiju" (a Chinese encyclopedia, literally "Collection of Literature Arranged by Categories"). Shichiyosho is considered to refer to yin yang (positive and negative, light and shade) of Five Phases theory and Wood, Fire, Earth, Metal, Water as symbols of the world.
How Fuhonsen coin was found
Fuhonsen coin was in the list of old coins in 1798 as 'Fuhon Shichiseisen' with illustrations and was known among coin researchers since early times. However, at that time it was considered as a coin used for incantation from the Edo period.
However, in recent years, it was excavated at the site of Heijo-kyo in 1969 and also at the site of Fujiwara-kyo, which is older than Heijo-kyo, in 1991. As the result, possibility arose that Fuhonsen coin was older than Wado-kaichin issued in 708, which had been considered as the oldest coin.
In 1995 a coin was unearthed at Kamikurisu ruins in Fujioka City, Gunma Prefecture.
In January, 1999, 33 Fuhonsen coins were discovered from Asukaikekobo ruins. Before that only five coins were discovered.
On 6 of 33, the letters '富本' were recognized and on 6 only '富' was recognized and on 5 only '本' was recognized and the others were small fragments. In the surrounding area of the nearly-completed coins, mold, izao (ways where copper run into), runner of molten copper, and ibari which is stray copper at casting were remained, by which those incomplete ones are considered as bad ones to be discarded.
From the stratum from which Fuhonsen coin was excavated, roof tile of a temple constructed before 700 and mokkan (a long and narrow wood plate written with a brush) marked 'Yin Fire Pig year' indicating the year 687 were excavated; furthermore in "Nihonshoki" (Chronicles of Japan) in 683 it was written 'Use copper coins from now on and do not use silver coins any more.'
Therefore Nara National Research Institute for Cultural Properties which had excavated them, announced on January 19 of the same year that it was older than Wado-kaichin and highly probable to have been casted in 683, which was publicized widely.
As the result, it was reported sensationally that 'the oldest coins were found' and 'history textbook must be revised.'
Subsequently in the additional survey after April, also defects, refuse, mold and molten copper were found. From the amount of molten copper, it was assumed that more than 9,000 coins were casted and it became clear that full-scale casting was done. Because the rate of antimony was almost the same as Wado-kaichin, it is assumed that it became the model of Wado-kaichin.
In March, 2008, it was announced that eight out of nine Fuhonsen coins which were packed in a flattened bottle which was discovered as ground-breaking equipment from Fujiwara Palace Site in November, 2007, had different calligraphic style from the traditional one. Four of those did not include antimony which was considered as characteristics of Fuhonsen coin.
Circulating money or incantation coin?
Because of the discovery, the theory that Fuhonsen coin was 'the first distributed coin' became widely accepted in academic meetings for a period of time. However, there is no evidence that it was widely distributed, so it cannot be said for sure that Fuhonsen coin is the oldest circulating money. Conversely, the possibility that it was made as incantation coin for religious purpose cannot also be ruled out.
Circulating money theory
Fuhonsen coin is in accordance with the description of "Nihonshoki" in 683.
Urban and temple construction led by the state needed enormous expenses and currency was necessary to pay organized people.
It is assumed that Mumon-ginsen coin (Japan's oldest private silver coin) was already used among the general public.
All the currency issuances in the history of Japan was circulating money and there is no record referring to those of incantation coin for religious purpose. It is unnatural to insist that only Fuhonsen coin was the incantation coin.
There is no need to make incantation coin so finely which was not used in actual exchanges.
Therefore the theory insists that it was issued in a planned manner by the Emperor Tenmu for the establishment of a new state.
Incantation coin theory
Considering the close relationship between politics and religion at the time, it is still possible that the description of "Nihonshoki" was written as regulation of incantation coin.
There is no record of an act that prohibits shichusen (counterfeit money) just after the issue of Fuhonsen coin, and such act was first established only after the issue of Wado-kaichin, which means shichusen was allowed if Fuhonsen coin was circulating money.
No record has been found that the standard was set to exchange old coins (fuhonsen) after Wado-kaichin was issued.
Even literature from the mid Nara period described that the first currency that as issued was Wado-kaichin in 708.
The Asukaikekobo ruins are located beside Asuka-dera Temple and it is appropriate to consider that the ruins were the affiliated facilities of either Asuka-dera Temple or a temporary authority (Zojishi [officials in charge of building temples]) called 'Zo Asuka-dera jishi.'
Therefore the theory has it that it is difficult to consider Fuhonsen coin was made to distribute.
Moreover, Mumon-ginsen coin is known as the older coin than Fuhonsen coin, and it is considered as Hyodo kahei (currency valued by weight) for barter exchange by the value of silver as raw metal. There are still many questions regarding the relationship between Fuhonsen coin and Wado-kaichin, the value as currency, region of distribution, the function, and so on, which merit further research.