The Apostle and first "Bishop of Rome", Peter, was imprisoned, tortured, and crucified in Rome in 64 CE under the Roman emperor, Nero. Some scholars set the date at October 13, 64 CE. The earliest documented mention of Peter's death is in a letter from Clement, bishop of Rome (AD 88-97), to the Corinthians. It is in "The Acts of Peter" (2nd century CE), that we find the story of Peter being crucified upside-down, supposedly at Peter's request, because was "unworthy to die in the same manner as my Lord."
Eusebius of Caesarea (275–339 CE) also records this story, but says his source is from a church theologian named Origen (who wrote about 230 CE): "Peter appears to have preached through Pontus, Galatia, Bithynia, Cappadocia, and Asia, to the Jews that were scattered abroad; who also, finally coming to Rome, was crucified with his head downward, having requested of himself to suffer in this way" (Ecclesiastical History 3:1).
The crucifixion took place during a spectacle that included battles between slaves, gladiators, and wild beasts. The Christians immediately took Peter's body and buried it in the cemetery near the Circus Maximus.
Peter was also known as Simon ben Johan/BarJonah, Simon Peter, Cephas, and Kepha. He was a Galilean fisherman. He was married (Matthew 8:14-5 and Mark 1:30-31). He may have also had a son (1 Peter 5:13).
(painting by Michelangelo Merisi da Caravaggio, The Crucifixion of Saint Peter, c. 1601)