Jōgan Eihō — The End of the Twelve Imperial Coins and Economic Transformation

Jōgan 12 (870) marked a significant turning point in ancient Japanese history. During Emperor Seiwa's reign, Fujiwara no Mototsune held actual power as regent, aiming to strengthen the imperial and Fujiwara power bases through economic policies. The Japanese economy was highly unsettled, with coin value depreciating and silk, cloth, and rice effectively serving as currency, especially in local areas where taxes were often paid in these goods, leading to fiscal difficulties for the government. Consequently, Jōgan Eihō was released as the ninth of the Twelve Imperial Coins, with the inscription 'Eihō' intended to signify perpetual circulation. However, actual circulation was regionally limited, failing to meet government expectations. The number of coins minted is unknown, with various theories suggesting it was minimal considering the economic conditions then. Jōgan Eihō's issuance was the government's attempt to stabilize the monetary economy, intertwined with political motives, cementing its significance in Japan's ancient coinage history.

The coinage of Jōgan Eihō was a culmination of the sophisticated technology and labor force of the time in Japan. The minting was conducted at the Mint Office established in Heijō-kyō, responsible for everything from copper mining to minting, essential for national finance. Craftsmen and laborers, drawing on Chinese technology and adding their innovations, contributed to the minting process. Jōgan Eihō was primarily made from copper, with small amounts of lead and tin added to ensure durability and ease of processing. Copper was mined in present-day Okayama and Hyōgo Prefectures and transported to the Mint Office. The process involved melting the copper, pouring it into molds, and hardening it. The molds were inscribed with 'Jōgan Eihō', beautifully embossed on the coin's surface through high-temperature baking. The extensive use of fuel led to deforestation, contributing to future environmental issues. The artisans, bearing the nation's fate, dedicated themselves to their daily work. Jōgan Eihō's minting was the fruit of their efforts and technology, resulting in a precious cultural legacy available for us to admire today.

After its issuance, Jōgan Eihō's circulation was limited to certain regions. The prevailing economic instability hindered smooth transactions using coins, with silk cloth and rice used predominantly as exchange means. In particular, in rural areas, coin circulation was restricted, and acceptance of Jōgan Eihō was limited. For instance, it is reported that areas corresponding to modern-day Nara and Kyoto saw relatively more circulation of Jōgan Eihō, whereas in rural areas, it was often unknown. In this context, Jōgan Eihō was primarily used in urban markets and trade, with little distribution in rural regions. The government aimed to stabilize the economy through Jōgan Eihō's issuance, but the impact was limited and did not lead to price stabilization. Consequently, the government struggled to continue coin issuance, leading to the cessation of minting in the following century. Jōgan Eihō's circulation and economic impact left significant lessons in Japan's monetary history.

Jōgan Eihō's circulation nearly ceased about 20 years after issuance, with coin minting completely halting in the next century. Yet, its impact persisted into later eras. As part of the Twelve Imperial Coins, Jōgan Eihō influenced subsequent monetary systems. The intention to stabilize the economy and centralize authority underpinned its issuance, affecting later policies. Particularly from the late Heian to Kamakura periods, Chinese imported coins circulated anew, leading to a near halt in domestic coin issuance. This ushered in significant changes in Japan’s monetary system, with increased trade and economic exchange with China. Additionally, Jōgan Eihō gained archaeological value due to its rarity, providing insights into the economy and society of its time through excavations. Jōgan Eihō stands as a symbol denoting a pivotal transition in Japanese history, passed down through generations. From this perspective, Jōgan Eihō maintains its vital position in Japan's monetary history.