 More significantly, Probus, by forcing from the vanquished tribes a tribute of manpower, established the precedent of settling barbarians within the empire as auxiliaries on a large scale.The provinces were depopulated by war, disease and the chaotic administration, heavy taxation, and extensive army recruitment, during the crisis of the Third century, and the barbarian colonies, at least in the short term, helped to restore frontier defense and the practice of agriculture.The army discipline which Aurelian had repaired was cultivated and extended under Probus, who was however more shy in the practice of cruelty.