# Constantine Roman emperor from 306 to 337, the first emperor to favor Christianity. He won the Battle of the Milvian Bridge outside Rome on 28 October 312 and credited the Christian God with the victory. In 313 he and his co-emperor Licinius agreed the policy known as the [Edict of Milan](/codex/edict-of-milan/), which gave Christians legal toleration and returned their confiscated property. In 325 he summoned the [Council of Nicaea](/codex/council-of-nicaea/). He was baptized on his deathbed at Nicomedia in May 337. He is also the most mythologized figure in church history. Popular claims say he invented the [Trinity](/codex/trinity/), picked the books of the Bible, or made Christianity the religion of the empire. All three are false. He convened Nicaea, but the bishops wrote its creed and held its faith long before he was born. He commissioned copies of Scripture but never ruled on the [canon](/codex/canon/). He made the faith legal and favored, not compulsory. Nicene Christianity became the state religion in 380, more than forty years after his death, under [Theodosius I](/codex/council-of-constantinople-i/). ## Life at a glance - **c. 272**, born at Naissus (modern Niš, Serbia), son of the officer Constantius Chlorus and Helena. - **306**, acclaimed emperor by the army in Britain after his father's death; years of civil war among rival emperors follow. - **28 October 312**, defeats Maxentius at the Milvian Bridge and takes Rome. - **February 313**, meets Licinius at Milan; the toleration policy that became the [Edict of Milan](/codex/edict-of-milan/). - **18 September 324**, defeats Licinius at Chrysopolis and becomes sole emperor. - **325**, convenes the [Council of Nicaea](/codex/council-of-nicaea/) over the Arian controversy. - **326**, has his eldest son Crispus and then his wife Fausta put to death; the circumstances are obscure. - **11 May 330**, dedicates Constantinople, his new eastern capital on the site of Byzantium. - **22 May 337**, dies near Nicomedia shortly after baptism by Eusebius of Nicomedia, a bishop sympathetic to Arius. ## The Milvian Bridge and the vision Two Christian writers who knew the period report a sign before the battle. Their accounts differ, and the difference is worth stating plainly rather than blending them into one story. | | Lactantius | Eusebius of Caesarea | |---|---|---| | **Work** | *Of the Manner in Which the Persecutors Died*, ch. 44 | *Life of Constantine* 1.28-29 | | **Written** | c. 314-315, within a few years of the battle | after Constantine's death in 337 | | **What happened** | a dream the night before battle | a sign in the sky at midday, seen by the army, then a dream of Christ that night | | **The sign** | a Christ monogram marked on the soldiers' shields | a cross of light above the sun with the words "conquer by this" | | **Source of the story** | Lactantius's own report | Constantine himself, years later, on oath | Lactantius, writing soon after the event, says that *"Constantine was directed in a dream to cause the heavenly sign to be delineated on the shields of his soldiers, and so to proceed to battle,"* and that he marked them with the cipher of Christ (Lactantius, *Of the Manner in Which the Persecutors Died* 44, ANF 7, PDF p. 286). Eusebius, in his later *Life of Constantine*, reports what the emperor *"long afterwards declared"* to him *"and confirmed his statement by an oath"*: that *"about noon"* he *"saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription, CONQUER BY THIS,"* and that his whole army saw it too (Eusebius, *Life of Constantine* 1.28, NPNF2 1, PDF p. 250). In chapter 29, Christ then appears to him in his sleep with the same sign. Two further points keep the record honest: - **Eusebius's own earlier account has no vision.** In the *Ecclesiastical History* he says only that Constantine, *"having invoked in prayer the God of heaven, and his Word, and Jesus Christ himself, the Saviour of all, as his aid,"* advanced on Rome (Eusebius, *Ecclesiastical History* 9.9, NPNF2 1, PDF p. 191). The sky-sign appears only in the later *Life*, on the emperor's word. - **The Latin slogan is later.** *In hoc signo vinces* is the familiar Latin form; Eusebius writes in Greek, and the NPNF translation renders it "conquer by this." What can be said with confidence: by 312 Constantine credited his victory to the God of the Christians and marked his army with a Christian sign. Whether he saw something in the sky, dreamed it, or later enlarged a dream into a vision, the sources do not settle. The codex does not need to settle it either; nothing in Christian apologetics rests on it. ## The Edict of Milan (313): toleration, not establishment The agreement Constantine and Licinius reached at Milan in February 313 granted every religion, Christianity by name, freedom of worship, and ordered confiscated churches and property returned with compensation from the imperial treasury to current holders. The text survives in Lactantius (ch. 48) and Eusebius (*Ecclesiastical History* 10.5). Full treatment at [Edict of Milan](/codex/edict-of-milan/). Three things it did not do: 1. **It did not make Christianity the state religion.** Traditional cults stayed legal and public. 2. **It did not ban paganism.** Its principle of liberty is stated for all religions. 3. **It did not create the church.** Christians had been a growing body for nearly three centuries, through the persecutions of Decius, Valerian and Diocletian. What it did was end imperial persecution and begin the move from tolerated minority to favored faith. Constantine then added privileges: exemptions for clergy, legal standing for bishops' courts, and imperial money for church building. In 321 he made Sunday a civil day of rest. Christians did not take Sunday from him; Justin Martyr already describes them gathering *"on the day called Sunday"* around AD 155 (Justin, *First Apology* 67, ANF 1, PDF p. 132). ## Nicaea (325): what he did and did not do The controversy began in Alexandria, where the presbyter Arius taught that the Son was the first and highest creature, not God in the full sense (see [Arianism](/codex/arianism/)). Constantine wanted church unity as a matter of imperial peace. He summoned the bishops to Nicaea, paid their travel, opened the council and attended its sessions. **What he did:** - Convened, hosted and funded the council. - Urged agreement. Eusebius of Caesarea's letter to his own church reports that the emperor endorsed the creed Eusebius read out and *"advised all present to agree to it ... with the insertion of the single word, 'One in substance'"* (*homoousios*) (letter preserved by Athanasius and Socrates; NPNF2 1, PDF p. 14; NPNF2 4, PDF p. 63). - Enforced the result at first, exiling Arius and the two bishops who refused to sign. **What he did not do:** - **He did not invent the Trinity.** The faith Nicaea defended was already confessed. [Tertullian](/codex/tertullian/) used *Trinitas* and "three persons, one substance" about a century earlier, and the New Testament already places Jesus inside the identity of the one God. Nicaea chose a precise word to exclude Arius's reading; it did not create the belief. The full case is at [Trinity Invented at Nicaea Objection Defeater](/codex/trinity-invented-at-nicaea-objection-defeater/) and [Trinity Invented at Nicaea Objection](/codex/trinity-invented-at-nicaea-objection/). - **He did not author the creed or vote as a bishop.** He was an unbaptized layman. The concession that he pressed for *homoousios* is real, and it cuts the other way from the myth: he endorsed a term the anti-Arian bishops wanted, for a doctrine they already held. - **He did not choose the books of the Bible.** No canon of Scripture was debated or decided at Nicaea. Constantine later ordered *"fifty copies of the sacred Scriptures"* from Eusebius for the churches of Constantinople (*Life of Constantine* 4.36, NPNF2 1, PDF p. 307), which is a copying order, not a canon ruling. See [The Canon Was Chosen Politically Objection Defeater](/codex/the-canon-was-chosen-politically-objection-defeater/) and [Canon](/codex/canon/). - **He did not stay Nicene.** Within a few years he recalled Arius, in 335 he exiled [Athanasius](/codex/athanasius/), Nicaea's leading defender, and he was baptized by an Arian-leaning bishop. An emperor who invented Nicene orthodoxy would not have spent his last decade undermining its champions. ## Theodosius and the Edict of Thessalonica (380): the actual establishment After Constantine, several emperors, Constantius II and Valens above all, favored the Arian or homoian side, and Julian (361-363) tried to restore paganism. The Nicene faith was a contested minority position at court for decades. The decisive legal act came on 27 February 380, when Theodosius I, with his co-emperors Gratian and Valentinian II, issued the edict *Cunctos populos* at Thessalonica (Codex Theodosianus 16.1.2). It required all subjects to hold the faith of the bishops of Rome and Alexandria, the one deity of Father, Son and Holy Spirit, and branded dissenters heretics liable to punishment. The [Council of Constantinople](/codex/council-of-constantinople-i/) in 381 completed the theological settlement. So the timeline runs: | Year | Event | Status of Christianity | |---|---|---| | 303-311 | Great Persecution | illegal, hunted | | 311 | Galerius's deathbed edict | grudgingly tolerated | | 313 | Edict of Milan | legally equal, then favored | | 325 | Council of Nicaea | favored; doctrine defined by bishops | | 337-379 | Arian-leaning emperors, Julian's pagan revival | contested | | 380 | Edict of Thessalonica | Nicene Christianity the state religion | ## Myths to avoid Apologists lose credibility when they answer one myth with another. Stay accurate in both directions. | Claim | Status | |---|---| | Constantine invented the Trinity at Nicaea | **False.** Bishops defined a term for a belief already held; see [Trinity Invented at Nicaea Objection Defeater](/codex/trinity-invented-at-nicaea-objection-defeater/). | | Constantine chose the books of the Bible | **False.** Nicaea did not discuss the canon. | | Constantine made Christianity the state religion | **False.** That was Theodosius in 380. | | Constantine invented Sunday worship | **False.** Sunday gatherings are attested by Justin c. 155; Constantine made Sunday a civil rest day in 321. | | Constantine voted the deity of Christ in by a narrow margin | **False.** Nearly every bishop signed; only a handful refused. | | Constantine was a model Christian ruler | **Overstated.** He had his son and wife killed in 326 and delayed baptism to his deathbed. | | Constantine had no real Christian commitment | **Overstated.** His legislation, church building and letters show sustained favor to the church from 312 on. | | The vision story is settled history | **Overstated.** The two earliest accounts differ, and the sky-sign rests on Constantine's later word. | ## In the codex's apologetic - **The Nicaea myth.** Constantine is the load-bearing name in the "Constantine invented Christianity" family of objections (Dan Brown's *The Da Vinci Code*, some popular atheist and Muslim polemic, Watchtower literature). The answer is chronological: the doctrine, the Scriptures and Sunday worship are all earlier than he is. See [Trinity Invented at Nicaea Objection Defeater](/codex/trinity-invented-at-nicaea-objection-defeater/). - **The power objection.** The codex concedes that after Constantine, and above all after 380, rulers used the faith to support their power. That concession is made openly at [Christianity Is Brainwashing Objection Defeater](/codex/christianity-is-brainwashing-objection-defeater/): the church grew for nearly three centuries without state help and often under state attack, so state favor cannot explain its origin. - **The "Constantinian compromise."** Many Christians, from Anabaptists to modern critics, argue the church lost something when it gained imperial favor. That is a debate within Christianity about faithfulness, not evidence that the faith was manufactured. See [Edict of Milan](/codex/edict-of-milan/). - **Primary sources.** Almost everything known about Constantine's faith comes from [Eusebius of Caesarea](/codex/eusebius-of-caesarea/), a partisan admirer, and from Lactantius. Use them, and name them, rather than repeating unsourced legend. ## See also - [Edict of Milan](/codex/edict-of-milan/), the 313 toleration policy in full - [Council of Nicaea](/codex/council-of-nicaea/), the council he convened in 325 - [Council of Constantinople I](/codex/council-of-constantinople-i/), Theodosius's council of 381 and the Edict of Thessalonica - [Trinity Invented at Nicaea Objection Defeater](/codex/trinity-invented-at-nicaea-objection-defeater/), the debate-prep answer to the Constantine myth - [Trinity Invented at Nicaea Objection](/codex/trinity-invented-at-nicaea-objection/), the concept hub on the same claim - [Christianity Is Brainwashing Objection Defeater](/codex/christianity-is-brainwashing-objection-defeater/), which concedes post-Constantine misuse of the faith - [Christianity Spread Only by the Sword Objection Defeater](/codex/christianity-spread-only-by-the-sword-objection-defeater/), the millions of Christians before 312 and the "only because of Constantine" claim - [The Canon Was Chosen Politically Objection Defeater](/codex/the-canon-was-chosen-politically-objection-defeater/), the canon myth answered - [Eusebius of Caesarea](/codex/eusebius-of-caesarea/), his biographer and the main source for the vision - [Athanasius](/codex/athanasius/), the Nicene champion Constantine exiled in 335 - [Arianism](/codex/arianism/), the teaching Nicaea rejected - [Ezana of Axum](/codex/ezana-of-axum/), the Axumite king who adopted Christianity around the same time - [Byzantine Church](/codex/byzantine-church/), the church of the eastern capital he founded - [Church History](/codex/church-history/), master hub
## Common questions this page answers **Q: Did Constantine invent the Trinity at the Council of Nicaea?** No. Constantine convened Nicaea in 325, but the bishops wrote its creed, and the faith it defended was already confessed. Tertullian spoke of the Trinity and of "three persons, one substance" about a century earlier. Constantine did urge the bishops to accept the word *homoousios* ("of one substance"), but that word was chosen to exclude Arius's view that the Son was a creature, not to create a new belief. **Q: Did Constantine make Christianity the official religion of the Roman Empire?** No. The Edict of Milan in 313 made Christianity legal and returned church property, but it granted freedom to every religion. Nicene Christianity became the state religion in 380, when Theodosius I issued the Edict of Thessalonica, more than forty years after Constantine died. **Q: Did Constantine decide which books went into the Bible?** No. The canon was not on the agenda at Nicaea, and Constantine never issued a ruling on it. He did order fifty copies of the Scriptures from Eusebius of Caesarea for the churches of Constantinople, but that was a copying order for books the churches already used. **Q: What did Constantine see before the Battle of the Milvian Bridge?** The two earliest accounts differ. Lactantius, writing around 314, says Constantine was told in a dream to mark his soldiers' shields with the sign of Christ. Eusebius, writing after 337 from what Constantine told him on oath, describes a cross of light above the sun at midday with the words "conquer by this," followed by a dream of Christ. Both agree that Constantine credited his victory to the Christian God. **Q: Was Constantine really a Christian?** He favored the church from 312 until his death, built churches, and legislated in its favor, but he was baptized only on his deathbed in 337, by a bishop sympathetic to Arius. He also had his son Crispus and his wife Fausta killed in 326. Historians still debate how deep his faith went; what is clear is that the church existed, grew, and held its core beliefs long before he came to power.