Emperor - the male ruler of an empire

Antoninus, Aurelius, Marcus Annius Verus, Marcus Aurelius, Marcus Aurelius Antoninus - Emperor of Rome; nephew and son-in-law and adoptive son of Antonius Pius; Stoic philosopher; the decline of the Roman Empire began under Marcus Aurelius (121-180)

Antonius Pius - Emperor of Rome; adoptive son of Hadrian (86-161)

Augustus, Gaius Julius Caesar Octavianus, Gaius Octavianus, Octavian - Roman statesman who established the Roman Empire and became emperor in 27 BC; defeated Mark Antony and Cleopatra in 31 BC at Actium (63 BC - AD 14)

Caligula, Gaius, Gaius Caesar - Roman Emperor who succeeded Tiberius and whose uncontrolled passions resulted in manifest insanity; noted for his cruelty and tyranny; was assassinated (12-41)

Claudius, Claudius I, Tiberius Claudius Drusus Nero Germanicus - Roman Emperor after his nephew Caligula was murdered; consolidated the Empire and conquered southern Britain; was poisoned by his fourth wife Agrippina after her son Nero was named as Claudius' heir (10 BC to AD 54)

Constantine, Constantine I, Constantine the Great - Emperor of Rome who adopted the Christian faith and stopped the persecution of Christians (280-337)

Decius - Emperor of Rome who was proclaimed emperor against his will; his reign was notable for his severe persecution of Christians (201-251)

Domitian, Titus Flavius Domitianus - Emperor of Rome; son of Vespasian who succeeded his brother Titus; instigated a reign of terror and was assassinated as a tyrant (51-96)

Adrian, Hadrian, Publius Aelius Hadrianus - Roman Emperor who was the adoptive son of Trajan; travelled throughout his empire to strengthen its frontiers and encourage learning and architecture; on a visit to Britain in 122 he ordered the construction of Hadrian's Wall (76-138)

Lucius Domitius Ahenobarbus, Nero, Nero Claudius Caesar Drusus Germanicus - Roman Emperor notorious for his monstrous vice and fantastic luxury (was said to have started a fire that destroyed much of Rome in 64) but the Empire remained prosperous during his rule (37-68)

Marcus Cocceius Nerva, Nerva - Emperor of Rome who introduced a degree of freedom after the repressive reign of Domitian; adopted Trajan as his successor (30-98)

Tiberius, Tiberius Claudius Nero Caesar Augustus - son-in-law of Augustus who became a suspicious tyrannical Emperor of Rome after a brilliant military career (42 BC to AD 37)

Titus Flavius Vespasianus, Titus Vespasianus Augustus, Titus - Emperor of Rome; son of Vespasian (40-81)

Marcus Ulpius Traianus, Trajan - Roman emperor and adoptive son of Nerva; extended the empire to the east and conducted an extensive program of building (53-117)

Titus Flavius Sabinus Vespasianus, Vespasian - Emperor of Rome and founder of the Flavian dynasty who consolidated Roman rule in Germany and Britain and reformed the army and brought prosperity to the empire; began the construction of the Colosseum (9-79)