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 290s decade ran from January 1, 290, to December 31, 299.
Year 293 (CCXCIII) 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 293 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 306 (CCCVI) was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius. The denomination 306 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 following outline is provided as an overview of and topical guide to ancient Rome:
Flavius Valerius Constantius, also called Constantius I, was a 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. While acting as Caesar under Emperor Diocletian, Galerius obtained victory warring against the Sassanian Empire, defeating Narseh at the battle of Satala in 298 and possibly sacking the Sassanian capital of 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 the Edict of Toleration in Serdica (Sofia) 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.
Nicomedia was an ancient Greek city located in what is now Turkey. In 286, Nicomedia became the eastern and most senior capital city of the Roman Empire, a status which the city maintained during the Tetrarchy system (293–324).
The Illyriciani or Illyrian emperors were a group of Roman emperors during the Crisis of the Third Century who were of Illyrian origins and hailed from the region of Illyricum, and were raised chiefly from the ranks of the Roman army.
Gamzigrad is an archaeological site, spa resort, and UNESCO World Heritage Site of Serbia, located south of the Danube river, in the city of Zaječar. It is the location of the ancient Roman complex of palaces and temples Felix Romuliana, built by Emperor Galerius in Dacia Ripensis. The main area covers 10 acres (40,000 m2).
The civil wars of the Tetrarchy were a series of conflicts between the co-emperors of the Roman Empire, starting from 306 AD with the usurpation of Maxentius and the defeat of Severus to the defeat of Licinius at the hands of Constantine I in 324 AD.
The Roman Milestones of Braga are a series of ancient road markers located in civil parish of Braga, municipality of Braga in northern Portugal.
The Five-Columns monument is a dedicatory addition to the Rostra in the Roman Forum dating to the early fourth century CE. This monument was part of the Tetrarchy's expansion of the Forum and is connected to the tenth anniversary of the Caesares within the four-ruler system. It is also referred to as the Fünfsäulendenkmal as well as the four-column monument, depending on Jupiter's inclusion.
The Legio I Illyricorum was a Roman Legion stationed in Qasr el-Azraq and Palmyra; it is mentioned in the Notitia Dignitatum. According to many ancient sources, it was stationed within the Eastern Half of the Roman Empire, under emperor Aurelian.
The Conference of Carnuntum was a military conference held on 11 November 308 in the city of Carnuntum, which at the time was located in the Roman province of Pannonia Prima. It was convened by the Eastern augustus (emperor) Galerius as a way to settle the dispute over the title of augustus in the West, and consequently, to cease the ongoing conflicts started the previous year when he, and before that Severus II, attempted to recover Italy from the usurpers Maxentius and Maximian. Present at the conference were the retired Diocletian, and his former colleague, Maximian.
The Battle of Brescia was a confrontation that took place during the summer of 312, between the Roman emperors Constantine the Great and Maxentius in the town of Brescia, in northern Italy. Maxentius declared war on Constantine on the grounds that he wanted to avenge the death of his father Maximian, who had committed suicide after being defeated by him. Constantine would respond with a massive invasion of Italy.
