Santi Marcellino e Pietro ad Duas Lauros

Santi Marcellino e Pietro ad Duas Lauros is a church in the Prenestino-Labicano quarter of Rome, Italy. Located on the ancient Via Labicana on land once owned by Helena, mother of Constantine, it was along the southern part of the Via Francigena.

History
The area known as Ad Duas Lauros ("to the two laurels") was the site of the necropolis of the Imperial Horse Guards. Around 320 Constantine I built a funerary basiica dedicated to saints Marcellinus and Peter over the Catacombs of Marcellinus and Peter. He then followed this with a large circular Mausoleum of Helena built against its eastern facade. The basilica was built with the apse facing the west. The catacombs were an important pilgrimage destination until the 9th century.

Its foundations weakened by the catacombs below, the building fell into disrepair. In 1256, Pope Alexander IV had the martyrs' relics translated to the recently rebuilt Santi Marcellino e Pietro al Laterano at the intersection of Via Labicana with Via Merulana.

Partly reusing its ruins, between 1632 and 1638, under Pope Urban VIII, a small Baroque church was erected dedicated to the two saints was built inside the mausoleum, then enlarged in 1765 during the pontificate of Pope Clement XIII.

A new neo-Romanesque parish church was constructed closer to the Via Casilina in 1922. The small church was de-consecrated.

Architecture
A three-arched portico is supported by two Corinthian columns. The simple façade has a balustraded window flanked by two niches and surmounted by a triangular tympanum.

The interior consists of a central nave of eight bays with side aisles; the first bay contains an internal entrance loggia and the last bay is a transept. The central nave is separated from the side aisles by arcades having five travertine limestone Doric columns on each side. The altarpiece is a painting of The Martyrdom of SS Marcellinus and Peter.