The following is a List of Roman wars and battles fought by the ancient Roman Kingdom, Roman Republic and Roman Empire, organized by date.
See Crisis of the Third Century
The 4th century begins with civil war resulting in the ascendancy of Constantine I, then, after his death, wars with Persia and Germanic tribes, punctuated frequently with more civil wars.
The 5th century involves the final fall of the Western Roman Empire to Goths, Vandals, Alans, Huns, and Franks.