The Tang dynasty or the Tang Empire was an imperial dynasty of China that ruled from 618 to 907. It was preceded by the Sui dynasty and followed by the Five Dynasties and Ten Kingdoms period in Chinese history. Historians generally regard the Tang as a high point in Chinese civilization, and a golden age of cosmopolitan culture. Tang territory, acquired through the military campaigns of its early rulers, rivaled that of the Han dynasty. The Tang capital at Chang'an (present-day Xi'an) was the most populous city in the world in its day.
Their coinage was limited - they cast mostly Kai Yuan cash coins (and a few other types), but rich number of varieties of these beautiful coins make the Tang coins very popular and collectible.