Who was Constantine?
In 'The Da Vinci Code,' Dan Brown says that Jesus' earliest followers believed that he was just a mortal man, a great teacher or prophet, but nothing more. He was made divine by a vote at the Council of Nicaea in 325 AD, at the insistence of the Roman Emperor Constantine. Although Constantine pretended to have converted to Christianity, he was actually a pagan emperor, who made Christianity the official religion of the Roman Empire for political reasons. The church leaders coerced him into being baptised on his death-bed.
So Brown has his expert Leigh Teabing say:
Jesus' establishment as the 'Son of God' was officially proposed and voted on by the Council of Nicaea.
Sophie asks him:
Hold on. You're saying that Jesus' divinity was the result of a vote?
A relatively close vote at that,
... says Teabing.
Brown also has one of his characters say,
Until that moment in history, Jesus was viewed by His followers as a mortal prophet.
And
...Constantine upgraded Jesus' status almost four centuries after Jesus' death...
So what are we to make of these claims? Constantine lived from about 273 to 337 AD, and became Emperor in 306 - sort of. The Roman Senate supported Maxentius as Emperor. War broke out between Constantine and Maxentius in 312 AD.
The outcome was settled at the Battle of the Milvian Bridge. Constantine won this battle, and secured his place as the sole ruler of the western half of the Empire. Constantine claimed that before the battle, he saw a cross in the sky, and the words 'In this sign conquer.'
He believed that the God of the Christians had helped him to win, and he converted to Christianity. Over the next twelve years, he strengthened his position, so that by 324 AD, he was the sole ruler of the whole Roman Empire. The next year, he called the Council of Nicaea.
Was he genuinely converted, or was it just a shrewd political move, as Dan Brown says? At this distance in time, there isn't any way we can be sure. However, what is clear is that Constantine's conversion did 'move the goalposts' for Christianity:
Before Constantine, Christians had often been persecuted for their beliefs. In 313 AD, Constantine and Licinius, the ruler of the eastern half of the Empire, together established toleration for all religions, by the Edict of Milan.
They didn't make Christianity the official religion of the Empire - but they did make it acceptable to be a Christian. And Constantine did pour a lot of money into building churches, and into having Bibles copied.
Dan Brown is quite right to say that Constantine was baptised on his deathbed, in 337 AD. Brown says that church leaders coerced him into this.
The reality is a bit more ordinary: in those days, people often waited until they were dying to be baptised. They thought that baptism washed away their sins. So it was just good tactics to leave it as late as possible, to make sure that all your sins were included.