Constantine Did Not Pick the Books

The story is everywhere: Constantine convened Nicea in 325 and the bishops decided which books would be in the Bible, discarding the ones that did not suit the emperor.
Nicea issued twenty rulings. None of them dealt with sacred writings. The council argued about the relationship of the Son to the Father - that is what produced the creed.
Lists of authoritative Christian writings were already circulating long before. The Muratorian Fragment dates to around 170 to 200 and names nearly the whole New Testament. Collections of Paul's letters were being assembled far earlier than that.
Constantine did affect the church in other ways, and after the council he instructed Eusebius to produce fifty Bibles for the churches of Constantinople. Commissioning copies of books already received is a different act from choosing them.
Scripture links:
- 2 Peter 3:15-16 - "as he does in all his letters... the other Scriptures."
- 1 Thessalonians 5:27 - "have this letter read to all the brothers."
- Colossians 4:16 - "have it also read in the church of the Laodiceans."
The canon was recognised over time, not voted in one afternoon.