A recent study by the University of Science and Technology of China (USTC) is rewriting history regarding how politics and industry interacted in early imperial China. Researchers in the university’s Archaeo-metallurgy Laboratory have tracked the evolution of bronze mirror making back to a time of economic recovery and state-backed reform during the reigns of Emperors Wen (180–157 BCE) and Jing (157–141 BCE) of the Western Han dynasty. Published in the Journal of Archaeological Science, the study revolves around the so-called “Panchi” mirrors—bronze artifacts with elaborate dragon motifs that were among the most prevalent mirror types of the period.
A Panchi bronze mirror with an intertwining dragons design. Warring States Period, Chu State. Unearthed at Zhangjiashan, Jiangling, Hubei Province, 1976. Credit: Cangminzho / CC BY-SA 4.0
The researchers analyzed 40 Panchi mirrors discovered in two public cemeteries in Lu’an, Anhui province. Dated between 221 and 141 BCE, the samples were analyzed for their decorative styles, inscriptions, chemical composition, lead isotope ratios, and trace elements. This close reading revealed two types of mirrors, each ᴀssociated with a distinctive technological and economic era. The earliest mirrors, heavily influenced by the Chu state, were produced with a high-lead, low-tin alloy from a short-lived metal supply. In the middle Western Han era, this method disappeared, giving way instead to a low-lead, high-tin alloy and a network of diversified copper—reflecting more formalized, state-coordinated forms of production.
Anchoring these changes to the reigns of Emperors Wen and Jing brings to mind the role of the early Han “Restoration and Recuperation” policy. This policy focused on stability, reduced heavy taxation, and fostered local industries, thus allowing crafts such as mirror-casting to flourish long before the more renowned expansion under Emperor Wu. Far from a boom, the study suggests that Emperor Wu’s later military and economic strength was based on decades of careful industrial development.
The study also sheds light on broader cultural shifts. Throughout the Warring States period and into the Han, bronze ritual vessels went out of favor with the rise of utilitarian bronzes such as coins and mirrors. Mirrors in particular shifted from being an elite ritual artifact to widely traded goods, their reverse decoration marking fashion and philosophy rather than ritual. The spread of Panchi mirrors from the Chu state along the Yangtze River to much of China during Western Han times is an indication of broader changes in artistic expression, regional idenтιтy, and state influence.
The authors argue that these movements in technology and style provide rare material evidence showing how state power, resource management, and market demand intersected during early imperial China. By linking alloy recipes, metal sources, and production trends to specific political periods, the study demonstrates that the Western Han’s industrial base—and by extension its military and economic strength—was neither accidental nor solely tied to Emperor Wu. Instead, it was built on the deliberate policies of his predecessors, which stabilized supply networks and promoted innovation in key industries like bronze mirror casting.
Ultimately, the USTC study places the humble bronze mirror into a wider perspective than that of a cosmetic tool. It is a window into an era when changing political priorities, shifting social values, and evolving technologies paved the way for one of China’s most powerful dynasties.
More information: Luo, Z., Liu, R., Pollard, A. M., Jin, Z., Liu, L., Gu, Y., … Fan, A. (2025). High-precision chronology and scientific analysis of Panchi mirrors reveal the state policy impact in early Imperial China. Journal of Archaeological Science, 180(106310), 106310. doi:10.1016/j.jas.2025.106310