The Crisis of the Third Century ( 235 â `` 284 AD ) was a period in which the Roman Empire nearly collapsed under the combined pressures of invasion , civil war , plague , and collapse of the economy . The Crisis is sometimes called the `` Military Anarchy '' or `` Imperial Crisis '' . The Crisis of the Third Century ( also `` Military Anarchy '' or `` Imperial Crisis '' ) ( 235 â `` 284 AD ) was a period in which the Roman Empire nearly collapsed under the combined pressures of invasion , civil war , plague , and economic depression .