Constantine I Declared Emperor
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Constantine I was born on 27 February 272 in the city of Naissus, Moesia Superior, modern day Niš, Serbia, the son of Flavius Consstantius, an army officer of the Roman Empire. While the date was recorded, the exact year was not, though research points to 272 being the correct year. His birth name is also not recorded, with his praenomen, or the first name chosen by his parents, was recorded as being Lucius, Marcus, or Gaius. He adopted the nomen, or patrlinial name, of emperor Diocletian 'Valerius'. His mother's name was Helena from Drepanum, which later became Helenopolis, in Bithynia, so she was likely a Greek-speaker, and it's uncertain whether she was a wife or a concubine. Constantine spoke Latin and needed a translator for meetings with the church councils, which were in Greek.
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In 286, emperor Diocletian divided the empire and declared Maximian his co-emperor for the western part of the empire, with Maximum ruling from Mediolanum, modern day Milan, Italy, or Augusta Treverorum, modern day Trier, Germany, while Diocletian ruled from Nicomedia, which is modern day İzmit, Turkey. In 288, Maximian chose Constitantius as his praetorian prefect, or chief of his personal security. The empire was officially divided in 293 with a caesar over the East and West and an augustus over each caesar, known later as the Tetrarchy. Constantius was promoted to caesar by Diocletian. He was then dispatched to Gaul to subdue a rebellion.
While the Tetrarchy was supposed to be a meritocracy and a move away from hereditary privilage, Constantine became Constintus' heir apparent. He served under Diocletian's court, where he received formal education, which included Latin literature, Greek, and philosophy. Nicomedia was an egalitarian city where Constantine was able to mix with intellectuals from pagan and Christian circles. Due to a great deal of mistrust between the Tetrarchs, Constantine was held against his father's good behavior, though he was a prominent member of the court and acted as general for several campaigns.
In 303, Diocletian began the 'Great Persecution', which was the 'most severe persecution of Christians in Roman history' after a messenger to the oracle of Apollo at Didyma returned with an imperial demand for universal persecutions. Churches were destroyed, scriptures burned, and treasures were seized with priests imprisoned and Christians deprived of official ranks. While Constantine didn't participate, his protests were not effective and this was held against him through the rest of his life.
In 305, Diocletian resigned due to illness. It was thought that he'd appoint Constantine and Maxentius, Maximian's son, as successors, though at the last moment of his resignation speech, he appointed Flavius Valerius Severus and Maximinus as caesars and Constantius and Galerius, Maximinus' uncle, as augusti. There are some sources that document Galerius' attempts to kill Constantine, including single combat with a lion. Constantius requested that his son be assigned to him, which Galerius granted after a supposed 'long evening of drinking'. Constantine was said to have fled, riding from post-house to post-house as quickly as possible, with his propaganda saying he hamstrung every horse he rode. He reached his father in Bononia, Gaul, modern day Boulogne-sur-Mer, on the north coast of France, by the summer of 305. With his father, he crossed to Eboracum, Britania, modern day York, England, where there was a large military base. He spent a year campaigning with his father in the north of Britania for a year, fighting the Picts north of Hadrian's Wall through the summer and autumn. It's unlikely that the campaign achieved a 'great success' in the area, though.
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Having suffered a growing illness, Constantius died on 25 July 306 in Eboracum. Before he died, he declared Constantine his successor. The Alamannic king, from a confederation of Germanic tribes in the Upper Rhine River region, Chrocus, who served under Constantius, supported Constantine's appointment as wel, going so far as to proclaim him augustus. This was also supported by Constantius' soldiers. While Britainia and Gaul supported his ascension, Hispania, which had been under Constantius for less than a year, did not. Constantine sent Galerius notice of his father's death and his rise to the throne, including a portrait of himself in the robes of an Augustus, claiming his troops 'forced' it upon him.
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Galerius nearly set the message and messenger on fire. He was calmed by his advisors, who pointed out that refusing Constantine's 'unlawful ascension' would lead to civil war. He compromised, only granting Constantine the title of caesar instead of augustus, appointing Flavius Valerius Severus as augustus. Wanting to make it perfectly clear that he held the power, Galerius sent Constantine the emperor's purple robes.
