History of the Republic of China elected Sun Yat-sen as the first Provisional President of the Republic of China. Yuan Shikai agreed to accept the Republic and forced the last emperor of China, Puyi, to abdicate on February 12. Empress Dowager Longyu signed the abdication papers. Puyi was allowed to continue living in the Forbidden City, however. The Republic of China officially succeeded the Qing Dynasty. Some advocated that a Han be installed as Emperor, either the descendant of Confucius, who was the Duke Yansheng, or the Ming dynasty Imperial family descendant, the Marquis of Extended Grace. On 1 January 1912, Sun officially declared the establishment
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).