3 Cash - Jiading Zhengbao, iron

The Jiading reign (1208–1224) was one of the most financially strained periods of the Southern Song, with the dynasty hemorrhaging resources fighting the Jin to the north while simultaneously debasing its currency through mass iron cash production. Iron coinage of this era was essentially an emergency measure — copper was too scarce and too strategically valuable to mint in volume. Jiading-era iron cash circulated at a fraction of their face value in practice, fueling persistent monetary instability in the Yangtze delta markets.

The three-cash denomination in iron was particularly short-lived as a trusted medium. Merchants routinely discounted iron multiples against copper singles.