The Wu Zhu denomination had been the backbone of Chinese bronze coinage since its introduction under Emperor Wu of Han in 118 BC, and by the time the Southern Dynasties were cycling through in rapid succession, the type had been debased and recast so many times that a single coin's nominal value bore little relationship to its metal content. The "Four pillar" variety — named for the structural reinforcing lines extending from the central square hole to the rim — was an attempt to address the chronic casting flaw of rim collapse in progressively thinner flans.
557 marks the collapse of the Liang dynasty and the founding of the Chen, the last of the Southern Dynasties before Sui reunification.
The Wu Zhu denomination had been the backbone of Chinese bronze coinage since its introduction under Emperor Wu of Han in 118 BC, and by the time the Southern Dynasties were cycling through in rapid succession, the type had been debased and recast so many times that a single coin's nominal value bore little relationship to its metal content. The "Four pillar" variety — named for the structural reinforcing lines extending from the central square hole to the rim — was an attempt to address the chronic casting flaw of rim collapse in progressively thinner flans.
557 marks the collapse of the Liang dynasty and the founding of the Chen, the last of the Southern Dynasties before Sui reunification.