The Transition of the Imperial Twelve Coins — From Wadō Kaichin to Kengen Taihō

In 708, during the reign of Empress Genmei, Wadō Kaichin, Japan's first full-fledged currency, was issued. This coin was minted in Heijō-kyō, Nara, and symbolized the centralization trend in Japan at the time. The Wadō Kaichin was about 4 grams, used high-purity copper, and was manufactured using advanced technology of the era. During this time, the government, led by Fujiwara no Fuhito, pushed forward the Ritsuryō system and attempted to strengthen the economic base by introducing currency. The issuance of Wadō Kaichin was modeled after China's Kaiyuan Tongbao, with intentions both to showcase the central government's authority and to promote trade transactions.

However, actual circulation did not proceed as expected, and the penetration of a monetary economy faced difficulties. Factors hindering the spread of currency included the continuing prevalence of bartering and insufficient currency supply. Moreover, although the minting quantity of coins was initially large, as the eras progressed, tendencies towards decreased weight and quality were observed. For example, while Wadō Kaichin had high copper purity, later coins suffered from a decline in this purity, and minting precision deteriorated. By the time of Kengen Taihō (958), minting precision was significantly lower compared to earlier coins. This decline in quality caused currency avoidance and led to the practice called 'sovereign picking,' considered a prototype for good coin selection.

The currency circulation during this period indicates a significant gap between the central government's policies and the actual living conditions of the populace. Moreover, the institutional foundation to support a monetary economy was immature, making it challenging for the government to establish the intended economic base. Please also refer to the overview and attraction of ancient coins.

The history of the Imperial Twelve Coins, which began with Wadō Kaichin, shows the transition of casting techniques and quality over time. The first Wadō Kaichin was made with high-purity copper, but as time went on, copper supply started to dwindle, leading to the inclusion of silver and lead. As a result, subsequent coins such as the Tenpyō Hōji coins (760s) and Jingū Kaihō (late 760s) gradually lost quality. Especially by the issuance of Kengen Taihō in 958, casting techniques had significantly deteriorated. The casting was initially centralized in Heijō-kyō but gradually dispersed to more local areas, contributing to the inconsistency in quality. Additionally, changes in the workforce involved in minting, with a decrease in skilled artisans, also accelerated the decline in quality. Factors such as prolonged political instability, warfare, and internal strife are thought to have influenced these developments. Consequently, circulating coins gradually lost trust and began to be avoided by the populace. By comparing with the types and identification of Edo period gold coins, the processes of technical development become more pronounced.

Initially, when the Imperial Twelve Coins began circulating in Japan, they were highly valued. However, as time went on and the quality of coins began to decline, public reaction gradually became cooler. By the time of Kengen Taihō, the lack of minting precision led to coins being avoided in circulation by the populace. This currency avoidance became known as 'sovereign picking,' characterized by the selection between good and bad coins. This phenomenon starkly illustrated the lack of trust within the monetary economy. Circulation stagnation caused price fluctuations, leading to issues with unstable exchange rates. For example, in some areas, grain trade reverted to primarily using rice as a key transaction method instead of currency. In response, the central government attempted reminting and currency collection, but effectiveness was limited. In such an economic environment, it became increasingly difficult for the populace to regain trust in currency. Explore further with the reference to types and identification of holed coins, delving deeper into the currency circulation and its impacts.

Following Kengen Taihō, the history of the Imperial Twelve Coins came to a close, but its impact extended to future generations. The failures in currency policy during this period became a crucial lesson in Japan's economic history, greatly influencing subsequent monetary systems. For example, from the late Heian to the Kamakura periods, coin minting nearly ceased, with bartering returning to prominence. Later, with the onset of the Edo period, coin minting resumed, and stringent quality control resulted in the circulation of more reliable coins. In this way, the failure of the Imperial Twelve Coins served as a lesson for building the foundation of later monetary policies. Additionally, the Imperial Twelve Coins serve as important clues in historical studies to understand the political and economic conditions of the time. Issues such as copper supply problems and changes in casting techniques highlight the technical limitations and political challenges of Japanese society during that era. Thus, these coins are evaluated for their historical significance beyond mere monetary value. Also, consider the types and features of commemorative coins to deepen your understanding of the historical value of coins.