The Mongols conquered the Muslim peoples of Central Asia even before they completed the destruction of the Song dynasty. They recruited many courageous Muslim warriors and skilled craftsmen into their armies; these were known as Hui forces. (Many were Uighurs; these people were called the Hui in Chinese.) They were very instrumental in the campaign to crush the remnant Southern Song dynasty.
東征西討的蒙古帝國，在尚未滅宋前就征服了中亞的回教國家，並且招降、征擄了不少驍勇善戰的回族軍人和技藝高超的工匠，軍隊納編為「探馬赤軍」，回鶻人佔大多數，元朝就稱他們為「回回軍」，成為日後征討南宋的重要幫手，回回也成為中國伊斯蘭的名字。