Explore 11 historical events from 300–309.
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 denomi…
Saint George, Roman soldier and martyr
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. As with other…
Diocletian and Maximian retire from the office of Roman emperor
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. As with other…
Diocletian and Maximian retired as co-rulers of the Roman Empire, being succeeded by Galerius and Constantius Chlorus
Sima Lun, courtesy name Ziyi (子彛), was titled the Prince of Zhao and the usurper of the Jin dynasty from 3 February to 31 May 301. He is usually not counted in the list of Jin empe…
Sima Lun, Chinese emperor (born 249)
Marcus Flavius Valerius Constantius, also called Constantius I, was a Roman emperor from 305 to 306—and was father of Constantine the Great, the first Christian emperor of Rome. He…
Constantius Chlorus, Roman emperor (born 250)
Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevati…
Constantine the Great was proclaimed Roman emperor by his troops after the death of Constantius Chlorus.
Saint Maginus was a Catalan hermit in the late third and early fourth centuries in Tarragona. Orphaned early, he was a hermit in a cave on Mount Brufaganya for thirty years.
Saint Maginus, Christian hermit and martyr from Tarragona
Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevati…
Constantine I is proclaimed Roman emperor by his troops.
San Marino, officially the Republic of San Marino (RSM), is a landlocked country in Southern Europe, completely surrounded by Italy. Located on the northeastern slopes of the Apenn…
San Marino, one of the smallest nations in the world and the world's oldest republic still in existence, is founded by…
Flavius Valerius Severus, also called Severus II, was a Roman emperor from 306 to 307, and a member of the Tetrarchy. He shared control of the western half of the empire with Const…
Flavius Valerius Severus, Roman emperor
Flavius Valerius Severus, also called Severus II, was a Roman emperor from 306 to 307, and a member of the Tetrarchy. He shared control of the western half of the empire with Const…
Flavius Valerius Severus, Roman emperor
Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevati…
Constantine I is proclaimed Roman emperor by his troops.
Marcus Aurelius Valerius Maxentius was a Roman emperor from 306 until his death in 312. Despite ruling in Italy and North Africa, and having the recognition of the Senate in Rome, …
Maxentius is proclaimed Roman emperor.
Marcus Flavius Valerius Constantius, also called Constantius I, was a Roman emperor from 305 to 306—and was father of Constantine the Great, the first Christian emperor of Rome. He…
Constantius Chlorus, Roman emperor (born 250)
Saint Maginus was a Catalan hermit in the late third and early fourth centuries in Tarragona. Orphaned early, he was a hermit in a cave on Mount Brufaganya for thirty years.
Saint Maginus, Christian hermit and martyr from Tarragona
Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevati…
Constantine the Great was proclaimed Roman emperor by his troops after the death of Constantius Chlorus.
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. As with other…
Diocletian and Maximian retire from the office of Roman emperor
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. As with other…
Diocletian and Maximian retired as co-rulers of the Roman Empire, being succeeded by Galerius and Constantius Chlorus
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 denomi…
Saint George, Roman soldier and martyr
San Marino, officially the Republic of San Marino (RSM), is a landlocked country in Southern Europe, completely surrounded by Italy. Located on the northeastern slopes of the Apenn…
San Marino, one of the smallest nations in the world and the world's oldest republic still in existence, is founded by…
Sima Lun, courtesy name Ziyi (子彛), was titled the Prince of Zhao and the usurper of the Jin dynasty from 3 February to 31 May 301. He is usually not counted in the list of Jin empe…
Sima Lun, Chinese emperor (born 249)