Task: Question Generation
Input (English): In 1271, Kublai Khan imposed the name Great Yuan (Chinese: 大元; pinyin: Dà Yuán; Wade–Giles: Ta-Yüan), establishing the Yuan dynasty. "Dà Yuán" (大元) is from the sentence "大哉乾元" (dà zai Qián Yuán / "Great is Qián, the Primal") in the Commentaries on the Classic of Changes (I Ching) section regarding Qián (乾). The counterpart in Mongolian language was Dai Ön Ulus, also rendered as Ikh Yuan Üls or Yekhe Yuan Ulus. In Mongolian, Dai Ön (Great Yuan) is often used in conjunction with the "Yeke Mongghul Ulus" (lit. "Great Mongol State"), resulting in Dai Ön Yeke Mongghul Ulus (Mongolian script: ), meaning "Great Yuan Great Mongol State". The Yuan dynasty is also known as the "Mongol dynasty" or "Mongol Dynasty of China", similar to the names "Manchu dynasty" or "Manchu Dynasty of China" for the Qing dynasty. Furthermore, the Yuan is sometimes known as the "Empire of the Great Khan" or "Khanate of the Great Khan", which particularly appeared on some Yuan maps, since Yuan emperors held the nominal title of Great Khan. Nevertheless, both terms can also refer to the khanate within the Mongol Empire directly ruled by Great Khans before the actual establishment of the Yuan dynasty by Kublai Khan in 1271.
Output (English): When did Khan establish the Great Yuan?