It is generally accepted that Peter was crucified upside down in Rome. Tertullian and Origen attest to this.

From WikiPedia:

According to the 1911 Catholic Encyclopedia, St. Peter labored in Rome during the last portion of his life, and there ended his life by martyrdom.[17] The death of St. Peter is attested to by Tertullian at the end of the 2nd century, and by Origen in Eusebius, Church History III.1. Origen says: "Peter was crucified at Rome with his head downwards, as he himself had desired to suffer."[17] This is why an upside down cross is generally accepted as a symbol of Peter, who would not have considered himself worthy enough to die the same way as his Savior.[35]

Whether or not Peter was bishop of Rome is still debated, although it is a belief held by the Catholic church. http://en.wikipedia.org/wiki/Saint_Peter#Connection_to_Rome

It is generally accepted that Peter was crucified upside down in Rome. Tertullian and Origen attest to this.

From WikiPedia:

According to the 1911 Catholic Encyclopedia, St. Peter labored in Rome during the last portion of his life, and there ended his life by martyrdom.[17] The death of St. Peter is attested to by Tertullian at the end of the 2nd century, and by Origen in Eusebius, Church History III.1. Origen says: "Peter was crucified at Rome with his head downwards, as he himself had desired to suffer."[17] This is why an upside down cross is generally accepted as a symbol of Peter, who would not have considered himself worthy enough to die the same way as his Savior.[35]

Whether or not Peter was bishop of Rome is still debated, although it is a belief held by the Catholic church.