Christians were severely persecuted in Rome beginning in 64 AD. One of the harshest periods – marked by property confiscation, incarcerations and executions – was during the reign of Diocletian from 284 until 305. In this time frame, practicing Christians worshipped in private homes called a titulus while other people disavowed their beliefs out of fear. When Constantine the Great became emperor in 306, he stopped the persecution. In 313, he passed the Edict of Milan providing religious tolerance. It was in this setting that Pope Marcellus was elected in 308. Although his papacy was short, he brought order back into the religion and established 25 parishes in Rome. Then he was arrested and died in captivity. The Church of St. Marcellus at the Corso was built in his name during the late 4th century and houses his remains. The structure has been destroyed, rebuilt and restored several times. The current version dates from the 16th and 17th centuries. This marble high altar was created by Sebastiano Cipriano in 1725. San Marcello al Corso is managed by the Servite Friars.
