100 Cash - Xianfeng Yuanbao, Boo-chiowan

The Xianfeng reign (1851–1861) produced some of the most chaotic coinage in Qing dynasty history. Facing the catastrophic drain of the Taiping Rebellion, the court authorized emergency high-denomination cash coins — 10, 50, 100, 500, and 1000 cash — in a desperate bid to fund military campaigns without depleting silver reserves. The 100 cash pieces from the Board of Revenue mint were among the first issued under this scheme, beginning in 1853.

Rapid debasement followed almost immediately. Within months of introduction, the brass content was quietly reduced and coin weights fell well below official standards. By 1855, public refusal to accept these overvalued pieces at face value was widespread enough that merchants in Beijing were openly discounting them.