Christianity in the roman empire.

[Jona Lendering]

or if not I would like to know who the first pope was, the chronological list of popes could not stretch so far.

The traditional answer is Peter, even though he is not mentioned in the Bible as ever visiting Rome, and his absence from Acts when Paul arrives in Rome is surprising. On the other hand, that may be explicable. I do not betray one of Christianity's mysteries when I say that Paul and Peter were not exactly on the best of terms. Personally, I think that the evidence for Peter's visit, although indirect, is sufficient. Clement, writing in the nineties of the first century, takes Peter's stay in Rome for granted. So, if by pope you mean "leader of the Christians of Rome", Peter's your answer. After that, the sequence of names is contested; still, the evidence from the catacombs -where many papal tombs were found- proves that the tradition is reliable from at least the third century onward.

Am I right in saying that there was such thing as 'the holy roman emperor'?

That title is usually used for the German emperor of the Middle Ages.