Was Jesus a real person?

[jason1990]

In another thread, Riddick wrote: "And regarding the birth of Jesus, isn't it widely regarded among our intellectual superiors and other high ranking historian-types, both atheist and not, that Jesus was in fact a real person?"

Is this widely regarded as a fact? If so, by whom? What evidence is there? Should the default assumption, in the absence of evidence, be that he is a fictional/mythical character that actually never existed? Do similarities between the story of Jesus and the stories of other mythical religious figures make it less likely that any of them existed as real people?