Okay. Why do you consider that reliable?
Were you aware of the other historians mentioned in the link I referenced... particularly the Romans? Did you consider those unreliable?
Do you mean like Tacitus?
I have no issue with him; I just think he and other Roman writers speak to the existence of
Christians, not to the existence of Christ.
Tacitus tells us, in part, that Christians were present in Rome as of the Great Fire, and that they believed that Jesus was real. This doesn't really tell us anything about whether Jesus really did exist.
Whether Jesus really existed as a god-man, existed as a historical figure who was embellished, was a composite of multiple historical figures (with some embellishment), or was completely fabricated from whole cloth, all of these hypotheses end up with Christians very quickly taking the story as true, so the mere fact that there were early Christians taking the Jesus story as true does nothing to help us pick one of these hypotheses as more likely than the others.
Edit: all we can really conclude from Tacitus (besides some stuff about Roman attitudes toward Christians) is that Christians - at least in Rome - started sincerely believing that Jesus was real some time before 64 AD.
Why they believed this or when this started aren't questions that Tacitus speaks to.