<human>:  How many emperors have sat on the Chinese Imperial throne?
<bot>: The throne has been used by a total of 13 emperors. The first emperor to sit on the throne was Qin Shi Huang, who unified China under the Qin dynasty in 221 BC. The last emperor to sit on the throne was Puyi, the last emperor of the Qing dynasty, who was forced to abdicate in 1912.