The initial 31 Semu categories referred to people who came from Central and West Asia. They had come to serve the
Yuan dynasty by enfranchising under the dominant Mongol caste. The Semu were not a self-defined and homogeneous ethnic group
per se, but one of the four castes of the Yuan dynasty: the Mongols, Semu (or Semuren), the "Han" (
Hanren in Chinese, or all subjects of the former
Jin dynasty,
Dali Kingdom (that would later become
tusis) and
Koreans) and the Southerners (
Nanren in Chinese, or all subjects of the former
Southern Song dynasty; sometimes called
Manzi). Among the Semu were
Buddhist Turpan Uyghurs of
Qocho,
Tanguts and
Tibetans;
Church of the East Christian tribes like the
Ongud;
Alans; Muslim Central Asian
Persian and
Turkic peoples including the
Khwarazmians and
Karakhanids; West Asian
Jewish and other minor groups who are from even further
Europe. While administratively classified as Semu, many of these groups rather referred to themselves by their self-aware ethnic identities in everyday life, such as the Uyghurs. Muslims, Persians, Karakhanids and Khwarazmians in particular, were actually mistaken to be Uyghurs or at least, "from the land of the Uyghurs". Therefore, they adopted the label conferred to them by the Chinese: "
Huihui", which was a corruption of the name Uyghur, but at the same time distinguishable from the name reserved for Buddhist Turpan Uyghurs proper, "Weiwuer". Of the many ethnic groups classified as "Semu" during the Yuan, only the Muslim Hui managed to survive into the
Ming period as a large collective identity with self-awareness of common identity spanning across the whole China. Other ethnic groups were either small and confined to limited localities (such as the Buddhist Turpan Uyghurs in
Wuling,
Hunan, and the
Kaifeng Jews), or were forced to assimilate into the
Han Chinese or Muslim Huis (such as some Christian and Jewish Semu in the Northwest, who, though thoroughly Islamicized, still unto this day retain peculiar labels like "Black Cap/
Doppa Huihui", "Blue Cap Huihui"). The historian Frederick W. Mote wrote that the usage of the term "social classes" for this system was misleading and that the position of people within the four-class system was not an indication of their actual social power and wealth, but just entailed "degrees of privilege" to which they were entitled institutionally and legally. Thus a person's "class" was not a guarantee of their social standing, since there were rich Chinese of good social standing, while there were fewer rich Mongols and Semu than there were ill-treated Mongols and Semu living in poverty. Major commerce during this era gave rise to favorable conditions for private southern Chinese manufacturers and merchants. When the Mongols placed the Uighurs of Qocho over the Koreans at the court the Korean King objected, then the Mongol Emperor Kublai Khan rebuked the Korean King, saying that the King of Qocho was ranked higher than the
Karluk Karakhanid khan, who in turn was ranked higher than the Korean king, who was ranked last, because the Uighurs surrendered to the Mongols first, the Karluks surrendered after the Uighurs, and the Koreans surrendered last, and that the Uighurs surrendered peacefully without violently resisting. ==Similar practices in other areas of the Mongol Empire==