The Kaiyuan Tongbao was first cast in 621 under Tang emperor Gaozu and became the backbone of Chinese bronze coinage for nearly three centuries — a longevity that generated enormous die variation and unofficial casting across dozens of provincial and military jurisdictions. By the late Tang period, central monetary authority had effectively collapsed, and coins were being produced by regional warlords, Buddhist monasteries, and military governors with minimal imperial oversight.
The crescent mark on the reverse is generally attributed to a fingernail impression made by a consort during the original Tang casting process — an origin story almost certainly apocryphal, but repeated in Chinese numismatic literature since the Song dynasty. More plausibly, such marks distinguished output from specific furnaces or casting supervisors during a period when accountability was entirely local.
The Kaiyuan Tongbao was first cast in 621 under Tang emperor Gaozu and became the backbone of Chinese bronze coinage for nearly three centuries — a longevity that generated enormous die variation and unofficial casting across dozens of provincial and military jurisdictions. By the late Tang period, central monetary authority had effectively collapsed, and coins were being produced by regional warlords, Buddhist monasteries, and military governors with minimal imperial oversight.
The crescent mark on the reverse is generally attributed to a fingernail impression made by a consort during the original Tang casting process — an origin story almost certainly apocryphal, but repeated in Chinese numismatic literature since the Song dynasty. More plausibly, such marks distinguished output from specific furnaces or casting supervisors during a period when accountability was entirely local.