Saints Marcellinus and Peter were two men martyred during the Diocletian persecutions in Rome during the 4th century.
The story of the two men was first told to Pope Damasus I who received their martyrdom story rom the jailor who executed both. Saint Marcellinus was a priest and Saint Peter an exorcist - both were arrested in the year 304 for being Christians, at the time a penalty of death from Emperor Dioceltian. Both were ordered to be executed at a location away from the city so that Christians would not come across their bodies and give them proper burial. Both Martyrs were lead a few miles away from Rome into a ticket containing brambles and thorns and both rejoiced in clearing the land cheerfully as they awaited their martyrdom. Both were beheaded.
Two women, having been given the location of the two martyrs bodies, had them property buried. Lucilla and Firmina buried their bodies near Saint Tiburtius's body on the Via Labicana. The jailor that performed the execution, a man by the name of Artemius, converted to Christianity after committing the act. A 6th century passio records that his wife and daughter converted to the Faith along side him and all three were eventually martyred for their conversion - Artemius was beheaded, his wife and sister buried alive under stones.
In the Martyrologium Hieronymianum, their feast day was set for June 2nd with their sepulcher was described as being located ad duas lauros (at the two Laurel trees). An original structure built by Pope Damasus honoring the martyrs was destroyed by the invading Goth army but Saint Constantine the Great rebuilt it as a basilica in their honor.
The two martyrs continue to be celebrated on their original feast day, June 2nd.