There is clearly evidence that--not only--was Peter in Rome, so was Paul. What there is no evidence of is that Peter served as the Bishop/Pope of the Roman Church. See below:
http://www.ccel.org/ccel/schaff/anf01.ix.iv.iv.html?highlight=succession,of,bishops,in,rome,linus,peter,and,paul#highlight
http://www.ccel.org/ccel/schaff/anf01.ix.iv.iv.html?highlight=succession,of,bishops,in,rome,linus,peter,and,paul#highlight
Chapter III.A refutation http://www.ccel.org/ccel/schaff/anf...,rome,linus,peter,and,paul#highlighthighlightof the heretics, from the fact that, in the various Churches, a perpetual succession of bishops was kept up.
1. It is within the power of all, therefore, in every Church, who may wish to see the truth, to contemplate clearly the tradition of the apostles manifested throughout the whole world; and we are in a position to reckon up those who were by the apostles instituted bishops in the Churches, and [to demonstrate] the succession of these men to our own times;
2. Since, however, it would be very tedious, in such a volume as this, to reckon up the successions of all the Churches, we do put to confusion all those who, in whatever manner, whether by an evil self-pleasing, by vainglory, or by blindness and perverse opinion, assemble in unauthorized meetings; [we do this, I say,] by indicating that tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul
3. The blessed apostles, then, having founded and built up the Church, committed into the hands of Linus the office of the episcopate. Of this Linus, Paul makes mention in the Epistles to Timothy.
What we clearly know from this passage, for those who consider it credible evidence, is that both Peter and Paul established the Church in Rome and appointed Linus to the office of the episcopate. It does not even imply that Peter was the Pope.1. It is within the power of all, therefore, in every Church, who may wish to see the truth, to contemplate clearly the tradition of the apostles manifested throughout the whole world; and we are in a position to reckon up those who were by the apostles instituted bishops in the Churches, and [to demonstrate] the succession of these men to our own times;
2. Since, however, it would be very tedious, in such a volume as this, to reckon up the successions of all the Churches, we do put to confusion all those who, in whatever manner, whether by an evil self-pleasing, by vainglory, or by blindness and perverse opinion, assemble in unauthorized meetings; [we do this, I say,] by indicating that tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul
3. The blessed apostles, then, having founded and built up the Church, committed into the hands of Linus the office of the episcopate. Of this Linus, Paul makes mention in the Epistles to Timothy.