Odoacer in the context of "Deposition of Romulus Augustulus"

This list of Roman civil wars and revolts includes civil wars and organized civil disorder, revolts, and rebellions in ancient Rome (Roman Kingdom, Roman Republic, and Roman Empire) until the fall of the Western Roman Empire (753 BC – AD 476). For the Eastern Roman Empire or Byzantine Empire after the division of the Empire in West and East, see List of Byzantine revolts and civil wars (AD 330–1453). For external conflicts, see List of Roman external wars and battles.

From the establishment of the Roman Republic in 509 BC until the 1st century BC, there were a sparse number of civil wars. But with the Crisis of the Roman Republic (134–44 BC), a period of considerable political instability began. The cause of the late Roman Republican civil wars is contested, as is whether the wars were the cause of, or caused by, the end of the Roman Republic. Regardless, a nearly constant stream of civil wars marked the end of the Roman Republic and heralded the rise of the Roman Empire in 27 BC. The first century of Empire was marked by widespread revolt through territory Rome had captured in the preceding centuries. The second century AD was relatively peaceful, with a limited number of revolts. Political instability returned to the Empire with the Crisis of the Third Century (235–284 AD), which saw at least 26 civil wars in just 50 years as usurpers sought the imperial throne. The fourth and fifth centuries AD were characterized by a regular rising of usurpers. The overthrow of the last Western Roman emperor in AD 476 by the Germanic king Odoacer marked the final civil war or revolt, as well as the end of the Western Roman Empire.

Romulus Augustus (c. 460-465) – (c. 511-530), nicknamed Augustulus, was Roman emperor of the West from 31 October 475 until 4 September 476. Romulus was placed on the imperial throne while still a minor by his father Orestes, the magister militum, for whom he served as little more than a figurehead. After a rule of ten months, the barbarian general Odoacer defeated and killed Orestes and deposed Romulus. As Odoacer did not proclaim any successor, Romulus is typically regarded as the last Western Roman emperor, his deposition marking the end of the Western Roman Empire as a political entity. The deposition of Romulus Augustulus is also sometimes used by historians to mark the transition from antiquity to the medieval period.

Very few records survive of Romulus's reign. There are no known policies, laws or inscriptions of significance of the emperor, which leaves the impression that he was a shadowy and relatively inconsequential figure. The nickname "Augustulus" means "little Augustus" and was a derisive reference to his young age. Romulus's immediate family, including his father and possibly his mother, and maybe both his paternal and maternal grandparents, were from the Roman province of Pannonia, and many of his family members had military backgrounds.

In the year before the First Council of Constantinople in 381, Nicene Christianity became the official religion of the Roman Empire when Theodosius I, emperor of the East, Gratian, emperor of the West, and Gratian's junior co-ruler Valentinian II issued the Edict of Thessalonica in 380, which recognized the catholic orthodoxy, as defined by the Council of Nicea, as the Roman Empire's state religion. Historians refer to this state-sponsored church using a variety of terms: the catholic church, the orthodox church, the imperial church, the Roman church, or the Byzantine church, with some also used for wider communions extending beyond the Roman Empire. The Eastern Orthodox Church, Oriental Orthodoxy, and the Catholic Church all claim to stand in continuity from the Nicene Christian church to which Theodosius granted recognition. Political differences between the Eastern Roman Empire and the Persian Sassanid Empire led to the separation of the Church of the East in 424. A doctrinal split within the imperial church led to the independence of early Oriental Orthodoxy, while the fall of the Western Roman Empire initiated the gradual separation between Eastern and Western Christianity, culminating in the East-West schism of 1054. The Western Church evolved into the Latin Catholic Church while the Eastern Church that remained under the patronage of the Eastern empire and evolved into the Greek Orthodox Church.

Earlier in the 4th century, following the Diocletianic Persecution of 303–313 and the Donatist controversy that arose in consequence, Constantine the Great had convened councils of bishops to define the orthodoxy of the Christian faith and to expand on earlier Christian councils. A series of ecumenical councils convened by successive Roman emperors met during the 4th and the 5th centuries, but Christianity continued to suffer rifts and schisms surrounding the theological and christological doctrines of Arianism, Nestorianism, Miaphysitism, and Dyophysitism. In the 5th century, the Western Roman Empire decayed as a polity; invaders sacked Rome in 410 and in 455, and Odoacer, an Arian barbarian warlord, forced Romulus Augustus, the last nominal Western Emperor, to abdicate in 476. However, apart from the aforementioned schisms, the church as an institution persisted in communion, if not without tension, between the East and West. In the 6th century, the Byzantine armies of the Byzantine Emperor Justinian I recovered Italy and other regions of the Western Mediterranean shore. The Byzantine Empire soon lost most of these gains, but it held Rome, as part of the Exarchate of Ravenna, until 751, a period known in church history as the Byzantine Papacy. The early Muslim conquests of the 7th–9th centuries would begin a process of converting most of the then-Christian world in the Levant, Middle East, North Africa, regions of Southern Italy and the Iberian Peninsula to Islam, severely restricting the reach both of the Byzantine Empire and of its church. Christian missionary activity directed from the capital of Constantinople did not lead to a lasting expansion of the formal link between the church and the Byzantine emperor, since areas outside the Byzantine Empire's political and military control set up their own distinct churches, as in the case of Bulgaria in 919.

The Ostrogothic Kingdom, officially the Kingdom of Italy (Latin: Regnum Italiae), was a barbarian kingdom established by the Germanic Ostrogoths that controlled Italy and neighbouring areas between 493 and 553. Led by Theodoric the Great, the Ostrogoths killed Odoacer, a Germanic soldier and erstwhile leader of the foederati. Odoacer had previously become the de facto ruler of Italy following his deposition of Romulus Augustulus, the final emperor of the Western Roman Empire, in 476. Under Theodoric, the Ostrogothic kingdom reached its zenith, stretching from Southern France in the west to Western Serbia in the southeast. Most of the social institutions of the late Western Roman Empire were preserved during his rule. Theodoric called himself "King of the Goths and Romans" (Latin: Gothorum Romanorumque Rex), demonstrating his desire to be a leader for both peoples.

Under Justinian I, the Byzantine Empire embarked on a campaign to reconquer Italy in 535. Witiges, who was the Ostrogothic ruler at that time, could not defend the kingdom successfully and was finally captured when the capital Ravenna fell. The Ostrogoths rallied around a new leader, Totila, and largely managed to reverse the conquest, but were eventually defeated. The last king of the Ostrogothic Kingdom was Teia.

The Ostrogoths (Latin: Ostrogothi, Austrogothi) were a Roman-era Germanic people who, in the 5th and 6th centuries, established one of the two major Gothic kingdoms within the Western Roman Empire. They drew on large Gothic populations settled in the Balkans since the 4th century and rose to prominence under Theodoric the Great, who in 493 founded the Ostrogothic Kingdom in Italy after defeating Odoacer.

Theodoric belonged to the Amal dynasty, which had gained power in Pannonia after the collapse of Attila’s Hunnic empire. Backed by the Byzantine emperor Zeno, Theodoric invaded Italy and established his rule from Ravenna, preserving Roman administration, law, and culture while governing Goths and Romans under parallel systems. His reign marked the height of Ostrogothic power and stability in Italy.

The Lombards, Longobards or Langobards (Latin: Langobardi) were a Germanic people who conquered most of the Italian Peninsula between 568 and 774 AD. They had previously settled in the Middle Danube in the 5th century, near what is now Austria, Slovenia and Hungary. Their previous homeland was in the north, near present day Hamburg. Roman-era historians in the 1st and 2nd centuries AD mention the Lombards as one of the Suebian peoples, and report them living on the Lower Elbe already in the early 1st century. Their legacy is apparent in Lombardy, northern Italy, the region deriving its name from them.

There are no contemporary accounts of the Lombards in the 3rd or 4th century, or for most of the 5th century, which is when they reappear, near the Danube river far to the south. Legendary accounts of the Lombard migration are found in several early medieval texts, the oldest being the Origo Gentis Langobardorum (Origin of the Lombard People). There are two other notable later adaptions, the Chronicon Gothanum and the more scholarly History of the Lombards by Paul the Deacon, written between 787 and 796 AD, which contain more information. All three describe the Lombards as a people who moved to the Danube from somewhere near the North Sea. The details, however, differ until they enter "Rugiland" soon after Odoacer's defeat in 487/488 AD of the Rugii, who had a kingdom near what is now Vienna.

The Kingdom of Italy (Latin: Regnum Italiae or Regnum Italicum; Italian: Regno d'Italia; German: Königreich Italien), also called Imperial Italy (Italian: Italia Imperiale; German: Reichsitalien), was one of the constituent kingdoms of the Holy Roman Empire, along with the kingdoms of Germany, Bohemia, and Burgundy. It originally comprised large parts of northern and central Italy. Its original capital was Pavia until the 11th century.

Following the fall of the Western Roman Empire in 476 and the brief rule of Odoacer, Italy was ruled by the Ostrogoths and later the Lombards. In 773, Charlemagne, the king of the Franks, crossed the Alps and invaded the Lombard kingdom, which encompassed all of Italy except the Duchy of Rome, the Republic of Venice and the Byzantine possessions in the south. In June 774, the kingdom collapsed and the Franks became masters of northern Italy. The southern areas remained under Lombard control, as the Duchy of Benevento was changed into the independent Principality of Benevento. Charlemagne called himself king of the Lombards and in 800 was crowned emperor in Rome. Members of the Carolingian dynasty continued to rule Italy until the deposition of Charles the Fat in 887, after which they once briefly regained the throne in 894–896.

The Rugii, Rogi or Rugians (Ancient Greek: Ρογοί, romanized: Rogoi), were one of the smaller Germanic peoples of Late Antiquity who are best known for their short-lived 5th-century kingdom upon the Roman frontier, near present-day Krems an der Donau in Austria. This kingdom, like those of the neighbouring Heruli and Sciri, first appears in records after the death of Attila in 453. The Rugii, Heruli, Sciri and others are believed to have moved into this region from distant homelands, and become part of Attila's Hunnic empire which also moved and came to be based in this region. The Rugii were subsequently part of the alliance which defeated Attila's sons and the Ostrogoths at the Battle of Nedao in 454, giving their kingdom independence. In 469 they were part of a similar alliance who lost to the Ostrogoths at the Battle of Bolia, weakening their kingdom significantly.

Many Rugii, once again along with Sciri, Heruli and other Danubians, joined Odoacer in Italy and became part of his kingdom there. Fearing new plots against him, he nevertheless invaded the Rugian kingdom in 487, and the Rugian lands were then settled by the Lombards from the north. Most Rugii still in the Danubian region eventually joined the Ostrogoth Theoderic the Great who killed Odoacer and replaced him with a Gothic-led regime in Italy. The Rugii were based in Pavia and played an important role in the Italian kingdom until it was destroyed by Justinian. The third last king was the Rugian Eraric who died in 541. After him these Rugii disappear from history.