The Tetrarchy was the system instituted by Roman Emperor Diocletian in 293 to govern the ancient Roman Empire by dividing it between two senior emperors, the augusti, and their juniors and designated successors, the caesares. This marked the end of the Crisis of the Third Century.
The 300s decade ran from January 1, 300, to December 31, 309.
The 310s decade ran from January 1, 310, to December 31, 319.
The 320s decade ran from January 1, 320, to December 31, 329.
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 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 Valerius. 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 293 (CCXCIII) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerius and Valerius. 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 250 (CCL) was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Traianus and Gratus. The denomination 250 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.
Year 307 (CCCVII) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerius and Constantius. The denomination 307 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 311 (CCCXI) was a common year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerius and Maximinus. The denomination 311 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 320 (CCCXX) was a leap year starting on Friday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantinus and Constantinus. The denomination 320 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 316 (CCCXVI) was a leap year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Sabinus and Rufinus. The denomination 316 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 a Roman emperor as one of the four original members of the "Tetrarchy" established by Diocletian in 293. He was a junior-ranking emperor, or Caesar, from 293 to 305, and senior emperor, Augustus, from 305 to 306. 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.
Gaius Galerius Valerius Maximianus was Roman emperor from 305 to 311. During his reign he campaigned, aided by Diocletian, against the Sassanid 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.
Galerius Valerius Maximinus, also known as Daza, was Roman emperor from 310 to 313. He became embroiled in the Civil wars of the Tetrarchy between rival claimants for control of the empire, in which he was defeated by Licinius. A committed pagan, he engaged in one of the last persecutions of Christians, before issuing an edict of tolerance near his death.
Marcus Aurelius Valerius Maxentius was a Roman emperor, who reigned from 306 until his death in 312. Despite ruling in Italy and North Africa, and having the recognition of the Senate in Rome, he wasn't recognized as a legitimate emperor by his fellow emperors.
Saint Proculus (Proclus) of Pozzuoli was martyred around 305 AD, according to Christian tradition, at the same time as Saint Januarius.
The Civil Wars of the Tetrarchy were a series of conflicts between the co-emperors of the Roman Empire, starting in 306 AD with the usurpation of Maxentius and the defeat of Severus and ending with the defeat of Licinius at the hands of Constantine I in 324 AD.
