Editing Constantine the Great (section)

=== In the East ===
Constantine received a formal education at Diocletian's court, where he learned Latin literature, Greek, and philosophy.{{sfnm|1a1=Barnes|1y=1981|1p=73–74|2a1=Lenski et al.|2pp=60|3a1=Odahl|3y=2001|3pp=72, 301}} The cultural environment in Nicomedia was open, fluid, and socially mobile; in it, Constantine could mix with intellectuals both pagan and Christian. He may have attended the lectures of Lactantius, a Christian scholar of Latin in the city.{{sfnm|1a1=Barnes|1y=1981|1p=73–74|2a1=Fowden|2y=1988|2pp=175–76}} Because Diocletian did not completely trust Constantius—none of the Tetrarchs fully trusted their colleagues—Constantine was held as something of a hostage, a tool to ensure Constantius' best behavior. Constantine was nonetheless a prominent member of the court: he fought for Diocletian and Galerius in Asia and served in a variety of [[tribune|tribunates]]; he campaigned against barbarians on the [[Danube]] in 296 and fought the Persians under Diocletian in Syria in 297, as well as under Galerius in [[Mesopotamia]] in 298–299.<ref>Constantine, ''Oratio ad Sanctorum Coetum'', 16.2</ref>{{sfnm|1a1=Elliott|1y=1996|1pp=29–30|2a1=Lenski et al.|2p=60|3a1=Odahl|3y=2001|3pp=72–74}} By late 305, according to some, he had become a tribune of the first order, a ''tribunus ordinis primi''.{{sfnm|1a1=Elliott|1y=1996|1pp=29–30|2a1=Lenski et al.|2p=60|3a1=Odahl|3y=2001|3pp=72–74}}{{sfn|Pohlsander|2004a|p=15}}

[[File:Romuliana Galerius head.jpg|thumb|left|[[Porphyry (geology)|Porphyry]] bust of Emperor Galerius]]
Constantine had returned to Nicomedia from the eastern front by the spring of 303, in time to witness the beginnings of Diocletian's "[[Diocletianic Persecution|Great Persecution]]", the most severe [[Persecution of Christians in the Roman Empire|persecution of Christians]] in Roman history.<ref>Constantine, ''Oratio ad Sanctorum Coetum'' 25</ref>{{sfnm|1a1=Elliott|1y=1996|1p=30|2a1=Odahl|2y=2001|2p=73}} In late 302, Diocletian and Galerius sent a messenger to the [[oracle]] of [[Apollo]] at [[Didyma]] with an inquiry about Christians.<ref>Lactantius, ''De Mortibus Persecutorum'' 10.6–11</ref>{{sfnm|1a1=Barnes|1y=1981|1p=21|2a1=Elliott|2y=1996|2pp=35–36|3a1=MacMullen|3y=1969|3p=24|4a1=Odahl|4y=2001|4p=67|5a1=Potter|5y=2004|5p=338}} Constantine could recall his presence at the palace when the messenger returned and Diocletian accepted the imperial court's demands for universal persecution.<ref>Eusebius, ''Vita Constantini'' 2.49–52</ref>{{sfnm|1a1=Barnes|1y=1981|1p=21|2a1=Odahl|2y=2001|2pp=67, 73, 304|3a1=Potter|3y=2004|3p=338}} On 23 February 303, Diocletian ordered the destruction of Nicomedia s new church, condemned its scriptures to the flames, and had its treasures seized. In the months that followed, churches and scriptures were destroyed, Christians were deprived of official ranks, and priests were imprisoned.{{sfnm|1a1=Barnes|1y=1981|1pp=22–25|2a1=MacMullen|2y=1969|2pp=24–30|3a1=Odahl|3y=2001|3pp=67–69|4a1=Potter|4y=2004|4p=337}} It is unlikely that Constantine played any role in the persecution.{{sfn|MacMullen|1969|pp=24–25}} In his later writings, he attempted to present himself as an opponent of Diocletian's "sanguinary edicts" against the "Worshippers of God",<ref>''Oratio ad Sanctorum Coetum'' 25</ref>{{sfn|Odahl|2001|p=73}} but nothing indicates that he opposed it effectively at the time. Although no contemporary Christian challenged Constantine for his inaction during the persecutions, it remained a political liability throughout his life.{{sfnm|1a1=Elliott|1y=1987|1pp=425–26|2a1=Lenski et al.|2p=126}}

On 1 May 305 Diocletian, as a result of a debilitating sickness taken in the winter of 304–305, announced his resignation. In a parallel ceremony in [[Milan]], Maximian did the same.{{sfnm|1a1=Barnes |1y=1981 |1pp=25–27 |2a1=Lenski et al. |2p=60 |3a1=Odahl |3y=2001 |3pp=69–72 |4a1=Pohlsander |4y=2004a |4p=15 |5a1=Potter |5y=2004 |5pp=341–342}} Lactantius states that Galerius manipulated the weakened Diocletian into resigning and forced him to accept Galerius' allies in the imperial succession. According to Lactantius, the crowd listening to Diocletian's resignation speech believed, until the last moment, that Diocletian would choose Constantine and Maxentius (Maximian's son) as his successors.<ref>Lactantius, ''De Mortibus Persecutorum'' 19.2–6</ref>{{sfnm|1a1=Barnes |1y=1981 |1p=26 |2a1=Potter |2y=2004 |2p=342}} It was not to be: Constantius and Galerius were promoted to ''augusti'', while [[Severus II|Severus]] and [[Maximinus Daza|Maximinus]], Galerius' nephew, were appointed their caesars respectively. Constantine and Maxentius were ignored.{{sfnm|1a1=Lenski et al. |1pp=60–61 |2a1=Odahl |2y=2001 |2pp=72–74 |3a1=Pohlsander |3y=2004a |3p=15}}

Some of the ancient sources detail plots that Galerius made on Constantine's life in the months following Diocletian's abdication. They assert that Galerius assigned Constantine to lead an advance unit in a cavalry charge through a swamp on the middle Danube, made him enter into single combat with a lion, and attempted to kill him in hunts and wars. Constantine always emerged victorious: the lion emerged from the contest in a poorer condition than Constantine; Constantine returned to Nicomedia from the Danube with a Sarmatian captive to drop at Galerius' feet.<ref>''Origo'' 4; Lactantius, ''De Mortibus Persecutorum'' 24.3–9; Praxagoras fr. 1.2; Aurelius Victor 40.2–3; ''Epitome de Caesaribus'' 41.2; Zosimus 2.8.3; Eusebius, ''Vita Constantini'' 1.21</ref>{{sfnm|1a1=Lenski et al. |1p=61 |2a1=MacMullen |2y=1969 |2p=32 |3a1=Odahl |3y=2001 |3p=73 }} It is uncertain how much these tales can be trusted.{{sfn|Lenski et al.|p=61}}