Emperor of China Emperor of China The Emperor or Huangdi () 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" (), a title much older than the "Emperor of China" which predates the Zhou dynasty and recognized as the ruler of ""All under
Emperor Taizong of Tang was no longer able to protect the last late-Sui rebel ruler who alone remained standing against Tang pressure – Liang Shidu the Emperor of Liang, and in summer 628, with the Tang generals Chai Shao and Xue Wanjun () sieging the Liang capital Shuofang (in modern Yulin, Shaanxi), Liang Shidu's cousin Liang Luoren () killed Liang Shidu and surrendered, finally uniting China. With the Eastern Turkish state weakened, their vassal Xueyantuo also broke away and formed its own khanate, and Emperor Taizong entered into an alliance with Xueyantuo's leader Yinan, creating Yinan the Zhenzhupiqie Khan (or Zhenzhu Khan in short).