Tuntian (屯田) or Tunken (屯墾) is a type of frontier "military-agricultural colonies" over the history of China. Troops were sent to harsh landscapes at the Chinese frontier to turn uncultivated land into self-sustained, agrarian settler colonies. In other words, the soldiers doubled as farmers. Han dynasty The Tuntian system or "Strategy of military farms" evolved during the famous victorious campaign of 61–60 BC by against the Qiang people, which presumed ancestors of the Tibetans. While the tuntian system was made famous by Cao Cao's administration ( 196–220 CE), Cao Cao's writings show that the system had been instituted as early as the Western Han dynasty during the reign of Emperor Wu ( 141–87 BCE), where soldiers on distant expeditions were set to work converting and farming the conquered land, both to provide food for the army and to convert the conquered land into agricultural land. After the death of Emperor Wu, however, the system was only used sporadically and therefore less effectively. The final years of the Eastern Han dynasty ( 189–220 CE) witnessed great economic disruption and widespread devastation, particularly through the Yellow Turban Rebellion of 184 CE; agricultural production in particular was severely disrupted, and population movements from war-ravaged areas led to massive flows of refugees. It was under these circumstances that Cao Cao's use of the tuntian system made its impact on the economic revival of China after the damage suffered previously. Method The mechanism of the 'civilian tuntian' system as implemented by Cao Cao had its basis in government organisation, encouragement and, to some extent, coercion. Peasants without land, refugees and soldiers were assigned to plots of land which they were to farm, while the implements required (such as ploughs and oxen) were provided by the government at a low price. In exchange for this, the peasant was to give over half of his harvest to the government. The tuntian system had its origins in the military, and for much of the Han dynasty the land in question was farmed by soldiers on orders of the military authorities; in this case all of the crop harvested was to be kept by the military for supply uses, following the example set by Emperor Wu. Cao Cao's innovation was the introduction of the 'civilian tuntian' on a large scale both for common people and for soldiers during peacetime, whereby he successfully solved two great economic problems facing his