Cathay (; ) is a historical name for China that was used in Europe. During the early modern period, the term Cathay initially evolved as a term referring to what is now Northern China, completely separate and distinct from China, which was a reference to southern China. As knowledge of East Asia increased, Cathay came to be seen as the same polity as China as a whole. The term Cathay became a poetic name for China. The name Cathay originates from the word Khitan, a name of a para-Mongolic nomadic people who ruled the Liao dynasty in northern China from 916 to 1125, and who later migrated west after they were overthrown by the Jin dynasty to form the Qara Khitai (Western Liao dynasty) for another century thereafter. Originally, this name was the name applied by Central and Western Asians and Europeans to northern China; the name was also used in Marco Polo's book on his travels in Yuan dynasty China (he referred to southern China as Mangi). Odoric of Pordenone (d. 1331) also writes about Cathay and the Khan in his travelbooks from his journey before 1331, perhaps 1321–1330. History The term Cathay came from the name for the Khitans. A form of the name Cathai is attested in a Uyghur Manichaean document describing the external people circa 1000. The Khitans refer to themselves as Qidan (Khitan small script: ; ), but in the language of the ancient Uyghurs the final -n or -ń became -y, and this form may be the source of the name Khitai for later Muslim writers. This version of the name was then introduced to medieval and early modern Europe via Muslim and Russian sources. The Khitans were known to Muslim Central Asia: in 1026, the Ghaznavid court (in Ghazna, in today's Afghanistan) was visited by envoys from the Liao ruler, he was described as a "Qatā Khan", i.e. the ruler of Qatā; Qatā or Qitā appears in writings of al-Biruni and Abu Said Gardezi in the following decades. The Persian scholar and administrator Nizam al-Mulk (1018–1092) mentions Khita and China in his Book on the Administration of the State, apparently as two separate countries (presumably, referring to the Liao and Song Empires, respectively). The name's currency in the Muslim world survived the replacement of the Khitan Liao dynasty with the Jurchen Jin dynasty in the early 12th century. When describing the fall of