[Collection Name]: Kaiyuan Tongbao

[Collection Age]: Tang Dynasty

[Collection Size]: Diameter 2.4 cm, Passing 0.7 cm. This collection is an old collection of Hai'an Museum, made of copper coins. The overall appearance is intact, with rust on the surface. The obverse of the coin has the four characters "Kaiyuan Tongbao" in the Li script. The calligraphy and casting techniques are exquisite, and it is a type of currency used in the Tang Dynasty.

Tongbao "is a name for copper coins in China from the early Tang Dynasty to the late Qing Dynasty. In the early days, weight was often used as the name for coins, such as half liang and five zhu, and later there were also names such as yuanbao and zhongbao. The Tang Dynasty changed the tradition of naming coins based on weight since the Qin and Han dynasties, and began to mint Kaiyuan Tongbao, which has a groundbreaking position in the history of Chinese coins. Kaiyuan "means opening up a new era; 'Tongbao' refers to the transportation of precious goods. At the same time, it represents the prosperity of the Tang Dynasty's economy and culture, and also witnesses the development process of Chinese currency.