1 Cash - Jiading Yuanbao, Han, iron

The Jiading reign (1208–1224) of Emperor Ningzong fell during a period of acute monetary stress in the Southern Song — copper shortages had become chronic enough that iron cash were issued not as a regional expedient but as a deliberate policy response. The Han circuit, covering much of modern Hunan, was one of several administrative regions authorized to strike iron currency independently, which accounts for the considerable variety in fabric and calligraphic style seen across surviving examples.

Iron cash from this period corrode aggressively in most soil conditions, making intact survivors with legible surfaces genuinely uncommon.