Was Peter’s crucifixion upside down? Can this be found in the scriptures or documented by any reliable source?
The only inference in the scriptures to the death of Peter in found in John 2:18, in which the Savior, speaking to Peter, says—
Verily, verily, I say unto thee, When thou wast young, thou girdedst thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall gird thee, and carry thee whither thou wouldest not.
The biblical scholar, Johann Jacob Westein, (1693-1754) made this commentary on John 2:18, as reported in Clarke’s Commentary, Matthew to Revelation [Nashville: Abingdon, n.d.], page 663,
“Wetstein observes that it was a custom at Rome to put the necks of those who were to be crucified into a yoke, and to stretch out their hands and fasten them to the end of it; and having thus led them through the city they were carried out to be crucified…. Thus then Peter was girded, chained, and carried whither he would not-not that he was unwilling to die for Christ; but he was a man -he did not love death; but he loved his life less than he loved his God….
“Ancient writers state that, about thirty-four years after this [After Jesus’ prophecy], Peter was crucified; and that he deemed it so glorious a thing to die for Christ that he begged to be crucified with his head downwards, not considering himself worthy to die in the same posture in which his Lord did. So [wrote] Eusebius, Prudentius, Chrysostom, and Augustin.
The earliest of these ancient writings was an apocryphal work, called th Acts of Peter, originally composed in Greek during the second half of the 2d century. This epistle concludes describing Peter’s martyrdom as upside-down crucifixion.