The name Roman Emperor refers to the supreme ruler and commander of the Roman Empire. The first Roman emperor was Augustus, who ruled from 19 BC to 14 AD. He was chosen because of the relationship he had with the Roman Senate. The reason for his death is unknown. Tiberius was the adopted son of Augustus, and took over the position in 14 AD, ruling until 37 AD. The next emperor was Caligula, who was the great-nephew to Tiberius. Guards and senators worked together to assassinate him in 41 AD, just four years after he took over the position.

Caligula�s uncle, Claudius, then took over the role of emperor and served until 54 AD. Historical legend claims that his wife killed him, so her son could rule the land. That boy, Nero, ruled until 68 AD, although he was only an adopted child to Claudius. When the Senate declared he was a public enemy, Nero killed himself.

Galba swept into power by joining forces with the Spanish. He remained emperor for only seven days before the Praetorian Guard had him killed. From January to April of 69 AD, Otho was the ruler, but after losing the Battle of Bedriacum, he killed himself. Until December of that year, Vitellius was emperor after taking over the throne with German help. He was murdered that same year. Vespasian then took over and seized the seat. He served until his death in 79 AD. His son, Titus, took over control and led until he too died in 81 AD. Vespian�s other son, Domitian, led from 81 AD to 96 AD when he was assassinated. The Senate then appointed Nerva, who ruled until 98 AD when he died. His adopted son Trajan would go on to rule until 117 AD, when he passed away.

Trajan�s adopted son Headrian then took control and led until 138 AD. Power passed to his son Antoninus Pius, who held the seat until his death in 161 AD. His adopted son Marcus Aurelius held power until he died in 180 AD. He was one of the only rulers to share the seat, as power was held with Lucius Verus from 161-169 AD. Commodus, the son of Marcus Aurelius, held the seat until 192 AD, when he was assassinated inside the palace walls. Pertinax took control, but held power for less than three months before his assassination.

Next, came Didius Julianus, an Italian who won the seat by auction. A few months later, the Senate had him executed. Septimius Severus took the role by force and held it from 193-211 AD, when he died. The role of emperor was held by a number of men working together until Elagabalus took control in 218, and held power until he was murdered in 222. Power passed to his adopted son Alexander Severus, who ruled until he was murdered in 235.

The Crisis of the Third Century brought new emperors into power. Maximinus Thrax held power from 235-238 when he was assassinated, and Gordian I proclaimed himself emperor. He killed himself just a few weeks later. Pupienus Maximus followed, but was assassinated three months later. His successor, Basbinus, was also assassinated while in office. Gordian III was also assassinated while in power, and Philip the Arab led from 244-249, when he died in battle. Decius then took over power, but was killed less than two years later.

His son Hostilian later took control and was followed by Trebonianus Gallus, Volusianus, Aemilianus, Gallus, Valerian and Gallienus. These emperors were followed by Claudius Gothicus, Quintillus, Aurelian, Tacticus, Florianus, Probus, Carus, Carinus and Numerian.

Diocletian was the first Roman emperor during the Tetrachy and Constantinian eras. He ruled until 305 AD, when he died. He was succeeded by Maximian, Constantius I, Galerius, Severus, Constantine I, Maxentius, Maximinius Daia, Lucinius and Constantine the II, who was killed in battle. Later successors who followed were Constantius II, Constans, Julian, and Jovian, who died in 364 AD, less than a year after taking over the role.

Valentinian I was the first ruler under the Valentinian era and led from 364 AD to his death in 375 AD. He was succeeded by his brother Valens, nephew Gratian, and nephew Valentinian II. The Theodosian era was marked by Theodosius I who ruled until 395 AD, Arcadius, Horonius who led until 423, Theodosius II, Constantius III, and Joannes as well as Valentinian III and Marcian.

Petronius Maximus was one of the last Roman emperors. He led for a few months in 455, until he was stoned by a mob. Avitus followed, as did Majorian, Libius Severus, Anthemius, Olybrius, Glycerius, Julius Nepos, and Roman Augustus. Many of these men were assassinated just a few months after taking over control.