The Tang Dynasty
Kai-Yuan-Tong-Bao; Mint Luo
Huichang Kaiyuan 845 AD cast from Buddhist statues
Reference: Hartill 14.77
Luo , Luoyang, the Capital in Henan
Obv: Kai Yuan Tong Bao (the Inaugural currency)
Rev: Luo on top
Huichang Kaiyuan 845 AD
In 845, in the Huichang period, the Emperor Wu Zong, a fervent follower of Taoism, destroyed the Buddhist monasteries and used the copper bells, gongs, incense burners and statues to cast coins in various localities. These local mints were under the control of the provincial governors. The New Tang History states that Li Shen, governor of Huainan province, requested that the empire might cast coins bearing the name of the prefecture in which they were cast, and this was agreed. These coins with mint names on the reverses, known as Huichang Kai Yuans, are of poor workmanship and size compared with the early Kai Yuans. However, when Emperor Xuanzong ascended to the throne the next year, this policy was reversed, and the new coins were recast to make Buddhist statues.
Kai Yuan Tong Bao
Kai Yuan Tong Bao (Chinese: 開元通寶; pinyin: kāiyuán tōng bǎo; literally: "The Inaugural Currency") were the main coin issued by the Tang. It was cast for most of the dynasty, a period of nearly 300 years. It was first issued by the Emperor Gao Zu in the autumn of the 4th year of the Wu De period (August 621). Its diameter was to be 8fen. The weight was set at 2.4 zhu, ten to the liang. 1,000 coins weighed 6 jin 4 liang. The legend was written by the famous calligrapher Ouyang Xun in a much admired mixture of the Bafen and Li (official or clerkly) styles of writing. This is the first to include the phrase tong bao, used on many subsequent coins. The inscription was used by other regimes in later periods; such coins can be distinguished from Tang coins by their workmanship. Minting and copper extraction were centrally controlled, and private casting was punishable by death. For the first time we find regulations giving the prescribed coinage alloy: 83% copper, 15% lead, and 2% tin. Previously the percentages used seem to have been on an ad hoc basis. Actual analyses show rather less copper than this.