Kaiyuan Tongbao
Tang, first cast 621 ・ bronze ・ 7th century ・ Tang
The copper coin the Tang cast in the fourth year of Wude (621). The four characters on the face read 'Kaiyuan Tongbao'; unlike the ban liang or the wu zhu, it no longer takes a weight for a name. Kaiyuan is not an era name here but means 'opening a new beginning' — and from this coin on, the copper coinage of China would follow the form of era name plus tongbao for more than a thousand years. The piece shown is an early type with a plain back.