The Crisis of the Third Century, also known as Military Anarchy or the Imperial Crisis (235–284 AD), was a period in which the Roman Empire nearly collapsed under the combined pressures of barbarian invasions and migrations into the Roman territory, civil wars, peasant rebellions, political instability (with multiple usurpers competing for power), Roman reliance on (and growing influence of) barbarian mercenaries known as foederati and commanders nominally working for Rome (but increasingly independent), plague, debasement of currency, and economic depression.