Illyrian emperors

Roman emperor from 306 to 337 and first to convert to Christianity (272–337)

Eastern Roman Emperor who ruled from 527 to 565 (482-565)

Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia. As with other Illyrian soldiers of the period, Diocles rose through the ranks of the military early in his career, serving under Aurelian and Probus, and eventually becoming a cavalry commander for the army of Emperor Carus. After the deaths of Carus and his son Numerian on a campaign in Persia, Diocles was proclaimed emperor by the troops, taking the name "Diocletianus". The title was also claimed by C

Aurelian (; ; 9 September ) was a Roman emperor from 270 to 275 during the Crisis of the Third Century. During his reign, he won an unprecedented series of military victories which reunited the Roman Empire after it had nearly disintegrated under the pressure of barbarian invasions and internal revolts. For his success in restoring the Empire's territorial integrity, Aurelian was honored with the title ("Restorer of the World").

Gaius Messius Quintus Trajanus Decius ( 201June 251), known as Trajan Decius or simply Decius (), was Roman emperor from 249 to 251.

Roman emperor (250-306)

Roman emperor (317-361)

Roman emperor from 364 to 375

Roman Emperor from 268 to 270 (213–270)

Valens (; ; 328 – 9 August 378) was Roman emperor from 364 to 378. Following a largely unremarkable military career, he was named co-emperor by his elder brother Valentinian I, who gave him the eastern half of the Roman Empire to rule. In 378, Valens was defeated and killed at the Battle of Adrianople against the invading Goths, which astonished contemporaries and marked the beginning of barbarian encroachment into Roman territory.

Valerius Licinianus Licinius (; Greek: Λικίνιος; c. 265 – 325) was Roman emperor from 308 to 324. For most of his reign, he was the colleague and rival of Constantine I, with whom he co-authored the Edict of Milan that granted official toleration to Christians in the Roman Empire. He was finally defeated at the Battle of Chrysopolis (AD 324), and was later executed on the orders of Constantine.

Maximian (; ), nicknamed Herculius, was Roman emperor from 286 to 305. He was Caesar from 285 to 286, then Augustus from 286 to 305. He shared the latter title with his co-emperor and superior, Diocletian, whose political brain complemented Maximian's military brawn. Maximian established his residence at Trier but spent most of his time on campaign. In late 285, he suppressed rebels in Gaul known as the Bagaudae. From 285 to 288, he fought against Germanic tribes along the Rhine frontier. Together with Diocletian, he launched a scorched earth campaign deep into Alamannic territory in 288, refo

3rd-century Roman Emperor (232-282)

Galerius Valerius Maximianus (; Greek: Γαλέριος; 258 – May 311) was Roman emperor from 305 to 311. He participated in the system of government later known as the Tetrarchy, first acting as caesar under Emperor Diocletian. In this period Galerius obtained victory warring against the Persian Sasanian Empire, defeating Narseh at the battle of Satala in 298 and possibly sacking the Sasanian capital of Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300. Galerius was promoted to augustus upon the abdication of Diocletian in 305, but had to contend

Roman emperor from 363 to 364

Marcus Aurelius Claudius Quintillus (died 270) was a short-lived Roman emperor. He took power after the death of his brother, Emperor Claudius Gothicus, in 270. After reigning for a few weeks Quintillus was overthrown by Aurelian, who had been proclaimed rival emperor by the legions he commanded. The ancient sources variously report him to have killed himself, to have fallen in battle against Aurelian, or to have been murdered by his own soldiers.

Emperor of the Byzantine Empire from 518 to 527 (450-527)

Marcian (; ; ; 392 – 27 January 457) was Roman emperor of the East from 450 to 457. Very little is known of his life before becoming emperor, other than that he was a (personal assistant) who served under the commanders Ardabur and his son Aspar for fifteen years. After the death of Emperor Theodosius II on 28 July 450, Marcian was made a candidate for the throne by Aspar, who held much influence because of his military power. After a month of negotiations Pulcheria, Theodosius' sister, agreed to marry Marcian. Zeno, a military leader whose influence was similar to Aspar's, may have been

Byzantine Emperor from 491 to 518

Gratian (; ; 18 April 359 – 25 August 383) was emperor of the Western Roman Empire from 367 to 383. The eldest son of Valentinian I, Gratian was raised to the rank of Augustus as a child and inherited the West after his father's death in 375. He nominally shared the government with his infant half-brother Valentinian II, who was also acclaimed emperor in Pannonia on Valentinian's death. The East was ruled by his uncle Valens, who was later succeeded by Theodosius I.

Hostilian (; died July 251) was briefly Roman emperor in 251. Hostilian was born to Decius and Herennia Etruscilla at an unknown date and elevated to caesar in 250 by Decius. After Decius and Herennius Etruscus, Hostilian's brother, were killed at the Battle of Abritus, an ambush by the Goths, Trebonianus Gallus was proclaimed emperor by the legions. Almost immediately, he elevated Hostilian to co-emperor and his own son, Volusianus, to caesar. Hostilian died soon after, either due to plague or being murdered by Trebonianus Gallus.

Roman emperor from 375 to 392

Roman emperor (220-251)

Group of Roman emperors