I rather think that Peter was a myth.
Romans died long before the Xians came. They took many of their burial practices from the Etruscans, who had very elaborate burial chambers that can still be viewed today.
The Romans also took from the Etruscans their eating practices (lying down on couches). I always thought of the last supper as the disciples lying 4 and 5 to a couch (crowded: 3 to a couch was optimum). Gives an insight to John lying in Jesus bosom....
The myth of Peter as head of the church was not promugated until the 4th century, and was never accepted by the Orthodox. Many of the supports of that myth are either ridiculous, or fraud.
Constantinius had reasons for moving his capital away from Rome, the Romans being part of that.
Why do you think that? There's more independent evidence (not to mention a contemporaneous epitaph on the site of his former burial place) for the existence of St. Peter than most of the Romans of the time.
I rather wonder why you think so, except some vague assumption that it couldn't *possibly* be true simply because it is has been maintained for 2000 years straight.
There is of course, no question that the Romans and the Etruscans borrowed many practices. Or that Romans buried their dead in necropoli (I have, in fact, been to the most famous Etruscan one at Cerveteri).
But what that has to do with St. Peter being a myth, I have no idea. To say nothing of the NT, the historical sources--*from the 2nd century* are unanimous in putting Peter in Rome. We have found his name scratched on graffiti in that necropolis below the cathedral.
Do you expect us to believe that an entirely different person of an entirely different name--both lost to history--headed the Christian community in Rome? A person apparently totally forgotten by everyone? And instead the Christian writers of the 1st and second century, who could name the succession from Peter to Linus to Clement and on, (oops!) just accidentally ascribed the founding to a made-up Galilean fisherman?
*Sigh*...how I tire of this modern fetish of "debunking".