The Emperor or Huangdi (Chinese: 皇帝; pinyin: Huángdì) was the secular imperial title of the Chinese sovereign reigning between the founding of the Qin dynasty that unified China in 221 BC and the abdication of Puyi in 1912 AD following the Xinhai Revolution and the establishment of the Republic of China, although it was later restored twice in two failed revolutions in 1916 and 1917. The holy title of the Chinese emperor was the Son of Heaven (Chinese: 天子; pinyin: tiānzǐ), a title much older than the Emperor of China which predates the Zhou dynasty and recognized as the ruler of “All under Heaven“ (i.e., the whole world). In practice not every Emperor held supreme power in China, although this was usually the case.
Emperors from the same family are classified in historical periods known as dynasties. Most of China’s imperial rulers have commonly been considered members of the Hanethnicity, although recent scholarship tends to be wary of applying present day ethnic categories to historical situations. During the Yuan and Qing dynasties China was ruled by ethnic Mongols and Manchus respectively. The orthodox historical view sees these as non-native dynasties that became sinicized, though some recent scholars (such as those of the New Qing History school) argue that the interaction between politics and ethnicity was far more complex. Nevertheless, in both cases these rulers claimed the Mandate of Heaven to assume the role of traditional Confucian emperors in order to rule over China proper.