Mamertine Prison

Mamertine Prison was originally built in 500-600BC and known as Tullianum. To begin with it was, in fact, not a prison at all, but an ancient cistern. It was later converted into a jail with two cells, one on top of the other. The entrance to the lower cell was a small door in the floor of the upper cell. The cells were dank dungeons where inmates rarely stayed long before they were executed.

Long-term incarceration was not really in vogue in the Roman Empire — execution or public humiliation was more de rigeur. There is some evidence that the captured foreign rulers or generals who were paraded during a Roman conqueror’s triumph were held and then executed later in the Mamertine Prison. These men may have included the Samnite Gaius Pontius, the Gaul Vercingetorix, and Jugurtha, King of Numidia.

The Mamertine Prison came to take on great significance for the Christians when it was believed that St. Peter had been imprisoned at the Tullianum, and that the spring at the bottom of the pit appeared miraculously to enable him to conduct baptisms. However, the spring existed before the prison, and there is really no evidence of his imprisonment here. They still built two churches on the site though, just in case.