A question from Yahoo! Answers:
When did Jesus become divine according to church decision?
Does anyone know the rough date of when the Catholic church made it definitive that Jesus was divine and created the trinity?
The divinity of Jesus was made a part of mainstream Christian doctrine at the First Council of Nicaea in 325. The doctrine of Holy Trinity was also finalized at the First Council of Nicaea, but subsequently modified at the First Council of Constantinople in 381.