Mongol Tumen Corps Organization

Timeline

1. 1206–1227source of the Onon River · Mongolian PlateauAfter the 1206 kurultai, Genghis Khan broke up and reorganized the tribes, appointing commanders of tens, hundreds, and thousands, with a tumen commander leading about ten thousand horsemen; thousand commanders were mostly meritorious officials or imperial clan members, forming a decimal military system capable of rapid mobilization.
2. 1227–1294Eurasia · Mongol EmpireDuring the western and southern campaigns, the tumen organization served as the basic tactical unit in battles and detachments; units below the thousand level could independently carry out reconnaissance, outflanking, and pursuit tasks, supporting transcontinental mobile warfare.
3. 1311–1320Golden Horde and Ilkhanate · IlkhanateIn the 1310s, under Golden Horde khan Özbeg and Ilkhan Abu Sa'id, the tumen and thousand organization remained the basic framework for recruitment and garrison duty, nominally inheriting the old system of the Great Mongol State.
4. c. 1350–1500various Mongol successor regimes · EurasiaAfter the Ilkhanate collapsed in 1335 and the Golden Horde split in the 15th century, the tumen organization was transformed locally into tribal or khanate court military systems; the decimal hierarchy was retained, but scale and subordination adjusted with political changes.