The eyebrow-raising claim of The Da Vinci Code is that Jesus was married to Mary Magdalene, one of the women who followed him around Israel as he travelled. After you get over the initial shock, it's the kind of claim that just seems to make a lot of sense. "Of course," we think. "Jesus would have been married, just like everyone else".

But is there any reason to think this is true beyond the general 'vibe' that it would make sense for a Jewish teacher to be married?

Some people say Jesus had to get married, because all rabbis (Jewish religious leaders) were required to. But Jesus wasn't a rabbi. He wasn't an official church leader, so the rules didn't apply to him. And there were other Jewish men who chose to be single in order to devote their lives to God (a bit like some monks and nuns in later centuries). Jesus even spoke about this himself (read Matthew 19:10-12).

So is there any hard data that tells us Jesus and Mary were a couple? Leigh Teabing, the Royal Historian in The Da Vinci Code, thinks so. He says: "the marriage of Jesus and Mary Magdalene is part of the historical record"

Is he right?

Not really. Not really at all.

To start with, the best historical documents about Jesus (the ones we have in the Bible) never say that he was married. There's nothing that even hints at it. Mary is significant in the New Testament, since she saw Jesus risen from the dead (read John 20:1-18). However, there is no suggestion that she had a special relationship with Jesus. In fact, there are plenty of places where this could have been mentioned, but isn't.

The idea that they were married comes from an interpretation of some ancient historical documents known as the Gnostic Gospels. These are fragments of writings from around 150-200 years after Jesus, which were found only in the last century. Two of them, The Gospel of Philip and The Gospel of Mary contain passages which talk about how much Jesus loved Mary Magdalene, and that he would sometimes kiss her. From these fragments of writing, which are more like ancient romance novels than history, some people have speculated that Jesus and Mary were a couple.

But they are making a huge leap in logic. In those Gnostic Gospels, it is also said that all the Christians kissed each other-it was their sign of greeting, not necessarily a passionate kiss. (The evidence of this is in 1 Corinthians 16:20 in the Bible.) What's more, the Gnostic Gospels are very incomplete and there are words and sentences missing. We can't even be sure of what they are saying about Jesus and Mary.

So why does the novel make such a big deal of this claim?

For starters, remember it is just a novel. The idea that Jesus and Mary had a family together makes for a great story. That's reason enough to suggest it.

But another intention of the novel seems to be to rescue Mary Magdalene from the claim that she was a prostitute. Some Christian traditions in the Middle Ages did teach that she was a "scarlet woman", probably the unnamed woman referred to in Luke 7:36-50. But this teaching had already been revoked and recognised as a mistake. Dan Brown needn't have bothered.

Dan Brown's main goal seems to be to make Jesus more human, and to make women more important to Christian spirituality. Both of these goals are good ones, but The Da Vinci Code isn't going to achieve it by playing loosely with history so that people can't really find out who the real Jesus and the real Mary Magdalene are.

The most reliable information on both of them is still the pages of the New Testament.