List of Roman civil wars and revolts in the context of "Roman Empire"

The War of Actium (32–30 BC) was the last civil war of the Roman Republic, fought between Mark Antony (assisted by Cleopatra and by extension Ptolemaic Egypt) and Octavian. In 32 BC, Octavian convinced the Roman Senate to declare war on the Egyptian queen Cleopatra. Her lover and ally Mark Antony, who was Octavian's rival, gave his support for her cause. Forty percent of the Roman Senate, together with both consuls, left Rome to join the war on Antony's side. After a decisive victory for Octavian at the Battle of Actium, Cleopatra and Antony withdrew to Alexandria, where Octavian besieged the city until both Antony and Cleopatra were forced to commit suicide.

The war involved some of the largest Roman armies ever seen. Both Antony and Octavian's legions were experienced veterans of previous civil wars who had fought together, many also having once served under Julius Caesar. The two did however raise their own legions separately.

The Crisis of the Third Century, also known as the Military Anarchy or the Imperial Crisis, was a period in Roman history during which the Roman Empire nearly collapsed under the combined pressure of repeated foreign invasions, civil wars and economic disintegration. At the height of the crisis, the Roman state split into three distinct and competing polities. The period is usually dated between the death of Severus Alexander (235) and accession of Diocletian (284).

The crisis began in 235 with the assassination of Emperor Severus Alexander by his own troops. During the following years, the empire saw barbarian invasions and migrations into Roman territory, civil wars, peasant rebellions and political instability, with multiple usurpers competing for power. This led to the debasement of currency and a breakdown in both trade networks and economic productivity, with the Plague of Cyprian contributing to the disorder. Roman armies became more reliant over time on the growing influence of the barbarian mercenaries known as foederati. Roman commanders in the field, although nominally loyal to the state, became increasingly independent of Rome's central authority.

The Pax Romana (Latin for 'Roman peace'; IPA: [paːks rɔːˈmaːna]) is a roughly 200-year-long period of ancient Rome that is identified as a golden age of increased and sustained Roman imperialism, prosperous stability, hegemonic power, regional expansion, and relative peace and order, although it still featured a number of internal revolts and external wars, including the Roman–Persian wars. Traditionally, the onset is understood to be the ascent of Augustus, who also founded the Roman principate, in 27 BC. Conversely, the end of the era is considered as 180 AD with the death of Marcus Aurelius, the last of the "Five Good Emperors".

It was during this period that the Roman Empire achieved its greatest territorial extent under Trajan in 117. Additionally, the Roman Empire's population is estimated to have peaked at 70 million people during the Pax Romana, accounting for 33% of the world's population. Following the Pax Romana, and according to Cassius Dio, the dictatorial reign of Commodus, later followed by the Year of the Five Emperors and the Crisis of the Third Century, marked Rome's descent "from a kingdom of gold to one of iron and rust".

This is a list of civil wars or other internal civil conflicts fought during the history of the Eastern Roman or Byzantine Empire (330–1453). The definition of organized civil unrest is any conflict that was fought within the borders of the Byzantine Empire, with at least one opposition leader against the ruling government. For external conflicts, see the list of Byzantine wars. For the period before the division of the Roman Empire in West and East, see List of Roman civil wars and revolts (753 BCE – 476 CE).

The following is a list of Roman external wars and battles fought by the ancient Roman Kingdom, Roman Republic and Roman Empire against external enemies, organized by date. For internal civil wars, revolts and rebellions, see List of Roman civil wars and revolts.