How was St Peter crucified?

Answer 1

2000 years of Catholic tradition state that Peter was crucified upside down in Rome under orders of Roman Emperor Nero. He did not feel he was worthy to die in the same manner as Jesus so requested that the soldiers crucify him head down. Even most non-Catholic theologians agree that Peter was crucified in Rome about AD 64 but the evidence that he was crucified upside down is weak and is based on tradition passed down by the early Church fathers. For more information please click on this link.

Answer 2

A third-century Christian tradition attributed to Origen is that the apostle Peter was crucified in Rome upside down at his own request, as he was not worthy of dying the same way of Christ had died. If we go back to the second century, we find the first known mention of St. Peter executed in Rome, when Pope Anicetus reported that Peter had been beheaded in Rome. Even further back in time, Clement of Rome, writing around 95 CE (1 Clement), spoke in general terms about the life and death of Peter but appears to have been unaware that he had even visited Rome and was certainly unaware that he had been executed. Although by omission, Clement provides the most reliable and timely information on the fate of Peter, which suggests he was not crucified, either upside down or in the normal way.

What we really know about St Peter is explained here.