The Mamertine Prison (also referred to as the Tullianum) was a prison (Carcer) located in the Forum Romanum in Ancient Rome. It was located on the northeastern slope of the Capitoline Hill, facing the Curia and the imperial forums of Nerva, Vespasian, and Augustus. Located between it and the Tabularium (record house) was a flight of stairs leading to the Arx of the Capitoline.

The Prison was constructed in around the time of the First Sack of Rome by Gauls, about 386 BC. It was originally created as a cistern for a spring in the floor of the second lower level (there were two, the lower of which was where prisoners were kept by lowering them through the floor of the upper room) however eventually a connection between the cistern drain and the Cloaca Maxima was made, reputedly for washing out dead bodies.

The name "Tullianum" supposedly comes from the King Tullus Hostilius or possibly King Servius Tullius (the latter supported by Livy, Varro, and also Sallust). The name "Mamertine" comes from a medieval misconception that it was the place where St. Peter was imprisoned before his execution.

Typically, only higher profile prisoners were kept in the prison, usually foreign commanders who were defeated and became the centerpiece in a Roman triumphant procession. They usually remained in the Tullianum until either they were taken out and executed or until they died by natural causes within the jail. However, no citizens were ever held in the Tullianum unless condemned, as Roman law did not recognize imprisonment as punishment.

It is not known when the Tullianum went out of service permanently, however the site is currently occupied by a small church.

External Links

• article Carcer in Platner's Topographical Dictionary of Ancient Rome
• chapter Carcer in Hülsen's Foro Romano

Persons held in the Tullianum: Jugurtha Vercingetorix