The following is an attempted list usurpers of the Roman Empire. For an overview of the problem and consequences of usurpation see Roman usurpers.

Key:

• kPG, killed by the Praetorian guard
• kS, killed by own soldiers
• kB, killed in battle
• e, executed
• dates are beginning and end of reign
• origin of the rebellion indicated where possible
• the list is complete until the advent of the tetrarchy in the end of the 3rd century

Emperor usurpers

This is a listing of Roman emperors that so became due to their own initiative with neither family ties to the previous nor senatorial appointement.

First Roman Imperial civil war: the year of the four emperors (69 AD)

• Otho – committed suicide
• Vitellius – killed
• Vespasian – secured the throne

From 193 to the tetrarchy (crisis of the third century)

• Septimius Severus (193-211) in the Rhine, secured the throne, founder of the Severan dynasty
• Macrinus (217-e.218) in Syria, former prefect of the Praetorian guard
• Maximinus Thrax (235-kS.238) in the Rhine, former centurion
• Gordian I and Gordian II (238) in Africa, suicide and death in battle
• Philip the Arab (244-kS.249) in the East, former prefect of the Praetorian guard
• Decius (249-kB.251) in Pannonia
• Aemilianus (kS.251) in Moesia
• Valerian (253-e.260) in the Rhine, executed by the Persians
• Aurelian (270-kPG275)
• …

Unsuccessful usurpers in the 3rd century

List of to be emperors eventually defeated by the ruling sovereign, listed by reign. The noted date is the attempted usurpation.

Heliogabalus: 218-222

• Gellius Maximus (219), in Syria, executed, originally an officer of Legio IV Scythica
• Verus (late 219), in Syria, executed, commander of Legio III Gallica
• Seleucus (after 221), in Moesia
• Uranius (around 221), questioned existence and date; sources place him in 253

Alexander Severus: 222-235

• Seius Sallustius (around 227), in Rome, executed, prefect of the Praetorian guard
• Taurinus (date unclear), in the East, committed suicide

Maximinus Thrax: 235-238

• Magnus (235), in the Rhine, a former consul
• Quartinus (235), in the East

Gordian III: 238-244

• Sabinianus (240), in Africa, governor of the province

Philip the Arab: 244-249

• Iotapianus (kS.248), in the East
• Pacatianus (kS.248), in the Danube frontier, killed by soldiers
• Silbannacus in the Rhine, questioned existence
• Sponsianus in Moesia, questioned existence

Decius: 249-251

• Priscus (249-k?252) in the East, Philip's brother
• Licinianus (250) in Rome, executed

Gallienus: 253-268

• Ingenuus (260) in Pannonia, committed suicide, former governor
• Macrianus Major, Macrianus Minor and Quietus (September 260 – Autumn 261) in the East, all killed by their own soldiers in different occasions
• Regalianus (260) in Pannonia, ruled with his wife
• Ballista (Autumn e.261) in the East, former Praetorian prefect, associated with the former
• Piso (kS.261) in Achaea, questioned existence
• Valens (k.261) in Achaea, killed by Macrinus, former governor
• Memor (e.261) in Egypt
• Mussius Aemilianus (261 - Spring e.262) in Egypt
• The emperors of the Gallic Empire
• The fictitious usurpers:
  • Celsus
  • Saturninus
  • Trebellianus

Claudius II: 268-270

• Censorinus (269-kS.270), questioned existence

Aurelian: 270-275

• Domitianus (270-271)
• Felicissimus (k.271) in Rome, a civil servant involved in corruption
• Septimius (kS.271) in Dalmatia
• Urbanus (271), questioned existence
• Firmus (k.273) in Egypt, questioned existence

Probus: 276-282

• Bonosus (280)
• Proculus (280)
• Saturninus (280)