Sts. Peter and Marcellinus were both martyrs from the early Church who are still honored today in the Eucharistic prayer that we offer at Mass.
Marcellinus was a well-known priest, and Peter was an exorcist—they lived during the persecution of Christians under the Roman emperor Diocletian at the start of the fourth century. They were arrested and jailed for being Christians.
In prison, they continued to proclaim the good news of Jesus Christ, which converted some of the prisoners, and even their guard (along with his wife and daughter). They were condemned to death by beheading, and were killed and buried in an unmarked place in the forest so that the Christian community could not honor their remains. Their executioner, who later became Christian himself, told of their location, however, and their bodies were found and placed in the catacombs.
The wall painting pictured here stood above their remains in the Roman catacombs—it shows Christ with the apostles, Peter and Paul, and below stand four saints. The middle of those four figures are inscribed with the names of the martyrs, Marcellinus and Peter.
Pope St. Damasus heard the story of their death from this executioner, and created an inscription for their tombs. Later, Constantine built a basilica over their remains—it is where his mother,
St. Helen, was buried. These two saints are honored in the Eucharistic prayer, and there is strong evidence that they were very important saints for the early Christian Church.
The bodies of Sts. Marcellinus and Peter were moved at several points through the ages, and ended up in a monastery in Germany. Relics of the martyr, St. Peter, also rest in the Basilica in the reliquary chapel.
Sts. Marcellinus and Peter, your imprisonment and death sentence did not dampen your zeal—pray for us!