The third-century crisis is a term used by historians to describe the political, military, and economic turmoil of the Roman Empire in the third century A.D. Frequent changes of rule, barbarian invasions, decline of urban centers, and the near destruction of long-distance commerce were all parts of this condition. It ended in 284 when Diocletian restored order by making fundamental changes in the Empire.
Historians evaluating archaeological evidence have determined from changes in the size of skeletons during this period the depth of famine that afflicted Europe during this, and later periods of the Roman decline.
The Earth and Its Peoples A Global History, Bulliet et al, 2005.