Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337, and the first to convert to Christianity. Born in Naissus, Dacia Mediterranea, he was the son of Flavius Constantius, a Roman army officer of Illyrian origin who had been one of the four rulers of the Tetrarchy. His mother, Helena, was a Greek Christian of low birth. She was a saint and is attributed with the conversion of her son. Constantine served with distinction under the Roman emperors Diocletian and Galerius. He began his career by campaigning in the eastern provinces before being recalled in the west to fight alongside his father in Britain. After his father's death in 306, Constantine became emperor. He was acclaimed by his army at Eboracum, and eventually emerged victorious in the civil wars against emperors Maxentius and Licinius to become the sole ruler of the Roman Empire by 324.
Pope Miltiades, also known as Melchiades the African, was the bishop of Rome from 311 to his death on 10 or 11 January 314. It was during his pontificate that Emperor Constantine the Great issued the Edict of Milan (313), giving Christianity legal status within the Roman Empire. The pope also received the palace of Empress Fausta where the Lateran Palace, the papal seat and residence of the papal administration, would be built. At the Lateran Council, during the schism with the Church of Carthage, Miltiades condemned the rebaptism of apostatised bishops and priests, a teaching of Donatus Magnus.
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 juniors colleagues 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 320s decade ran from January 1, 320, to December 31, 329.
Year 313 (CCCXIII) was a common year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantinus and Licinianus. The denomination 313 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. This year is notable for ending of the persecution of Christians in the Roman Empire.
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 Severus and Maximinus. 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 310 (CCCX) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Andronicus and Probus. The denomination 310 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 315 (CCCXV) was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantinus and Licinianus. The denomination 315 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.
Gaius 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.
Valerius Licinianus Licinius 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, AD 313, that granted official toleration to Christians in the Roman Empire. He was finally defeated at the Battle of Chrysopolis, and was later executed on the orders of Constantine I.
Galerius Valerius Maximinus Daza, also known as Daza, was Roman emperor from 310 to 313 CE. 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 was not recognized as a legitimate emperor by his fellow emperors.
The Diocletianic or Great Persecution was the last and most severe persecution of Christians in the Roman Empire. In 303, the emperors Diocletian, Maximian, Galerius, and Constantius issued a series of edicts rescinding Christians' legal rights and demanding that they comply with traditional religious practices. Later edicts targeted the clergy and demanded universal sacrifice, ordering all inhabitants to sacrifice to the gods. The persecution varied in intensity across the empire—weakest in Gaul and Britain, where only the first edict was applied, and strongest in the Eastern provinces. Persecutory laws were nullified by different emperors at different times, but Constantine and Licinius' Edict of Milan in 313 has traditionally marked the end of the persecution.
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.
The Religious policies of Constantine the Great have been called "ambiguous and elusive." Born in 273 during the Crisis of the Third Century, Constantine the Great was thirty at the time of the Great Persecution. He saw his father become Augustus of the West and then shortly die. Constantine spent his life in the military warring with much of his extended family, and converted to Christianity sometime around 40 years of age. His religious policies, formed from these experiences, comprised increasing toleration of Christianity, limited regulations against Roman polytheism with toleration, participation in resolving religious disputes such as schism with the Donatists, and the calling of councils including the Council of Nicaea concerning Arianism. John Kaye characterizes the conversion of Constantine, and the Council of Nicea that Constantine called, as two of the most important things to ever happen to the Christian church.
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.
