Diocletian, 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. Diocles rose through the ranks of the military early in his career, 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 Carus's surviving son, Carinus, but Diocletian defeated him in the Battle of the Margus.
The Tetrarchy was the system instituted by Roman emperor Diocletian in 293 AD to govern the ancient Roman Empire by dividing it between two emperors, the augusti, and their junior colleagues and designated successors, the caesares.
The 300s decade ran from January 1, 300, to December 31, 309.
The 310s decade ran from January 1, 310, to December 31, 319.
Year 286 (CCLXXXVI) was a common year starting on Friday of the Julian calendar. At the time, it was known as the Year of the Consulship of Maximus and Aquilinus. The denomination 286 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 305 (CCCV) was a common year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius. The denomination 305 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
The 290s decade ran from January 1, 290, to December 31, 299.
The 280's decade ran from January 1, 280, to December 31, 289.
Year 299 (CCXCIX) was a common year starting on Sunday of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Diocletian and Maximian. The denomination 299 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 303 (CCCIII) was a common year starting on Friday of the Julian calendar. It was known in the Roman Empire as the Year of the Consulship of Diocletian and Maximian. The denomination 303 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 294 (CCXCIV) was a common year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and(Galerius) Maximianus. The denomination 294 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 296 (CCXCVI) was a leap year starting on Wednesday of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Diocletian and Constantius. The denomination 296 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 288 (CCLXXXVIII) was a leap year starting on Sunday of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Maximian and Ianuarianus. The denomination 288 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Flavius Valerius Constantius "Chlorus", also called Constantius I, was Roman emperor from 305 to 306. He was one of the four original members of the Tetrarchy established by Diocletian, first serving as caesar from 293 to 305 and then ruling as augustus until his death. Constantius was also father of Constantine the Great, the first Christian emperor of Rome. The nickname Chlorus was first popularized by Byzantine-era historians and not used during the emperor's lifetime.
Galerius Valerius Maximianus was Roman emperor from 305 to 311. During his reign he campaigned, aided by Diocletian, against the Sasanian Empire, sacking their capital Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300. Although he was a staunch opponent of Christianity, Galerius ended the Diocletianic Persecution when he issued an Edict of Toleration in Serdica in 311.
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, refortifying the frontier.
Narseh was the seventh Sasanian King of Kings of Iran from 293 to 303.
Marcus Aurelius Mausaeus Carausius was a military commander of the Roman Empire in the 3rd century. He was a Menapian from Belgic Gaul, who usurped power in 286, during the Carausian Revolt, declaring himself emperor in Britain and northern Gaul. He did this only 13 years after the Gallic Empire of the Batavian Postumus was ended in 273. He held power for seven years, fashioning the name "Emperor of the North" for himself, before being assassinated by his finance minister Allectus.
The Conference of Carnuntum was a military conference held on November 11, 308 in the city of Carnuntum, which at the time was located in the province of Pannonia Prima. It was convened by the senior emperor of the East (Augustus) Galerius as a way to settle the dispute over the title of Augustus of the West and, consequently, to cease the ongoing conflicts since the previous year when he, and before that Severus II', invaded the Italy of Maxentius (r306-312) and Maximian. Present at the conference were Diocletian, who had been retired since 305, and Maximian.
The history of the Later Roman Empire covers the history of the Roman Empire from the beginning of the rule of Diocletian in 284 AD and the establishment of the Tetrarchy in 293 AD by Diocletian to the death of Heraclius in 641 AD.
