The council that defined Christian orthodoxy, and the favorite villain of conspiracy histories.
Stories
Constantine edited the Bible
Popularized by The Da Vinci Code and earlier writers: Constantine convened Nicaea to pick which gospels belonged in the Bible and to invent or suppress the divinity of Jesus, burning rival scriptures.
Assessment: False on the record. Nicaea's surviving canons deal with church administration and the date of Easter; its creed addressed the Arian dispute over Christ's nature. The biblical canon was not on the agenda and formed gradually over surrounding centuries.
Documented
What actually happened
Around 318 bishops gathered to settle whether Christ was of the same substance as the Father. The Nicene Creed resulted. Arius lost, was exiled, and his theology later returned anyway. The gospel selection popularly blamed on Nicaea was a long process across the 2nd through 4th centuries, finalized by consensus, not by one council.
Assessment: Documented by the council's own acts and letters from attendees like Eusebius.
Interesting claims
Suppressed gospels hide the real Jesus
The discovery of the Nag Hammadi library in 1945 revealed genuine suppressed texts, Gnostic gospels like Thomas and Philip, with sayings and frameworks excluded from the canon.
Assessment: The suppressed texts are real and worth reading. But scholars date most of them later than the canonical gospels; "hidden original truth" overstates what they are.
Sources and further reading
Eusebius, Life of Constantine 3.6-14, the council convoked
Athanasius, De Decretis, on homoousios
Socrates Scholasticus, Historia Ecclesiastica 1.8-9
Worth asking
Why do people prefer the story of one powerful man editing truth over the slower, messier truth of centuries of argument?