Santi Marcellino e Pietro al Laterano is an 18th century parish and titular church of ancient foundation at Via Labicana 1 in the rione Monti. Pictures of the church at Wikimedia Commons are here. An English Wikipedia page is here.
The Diocese now refers to this church as Santi Marcellino e Pietro al Laterano so as to distinguish the two parish churches, and it has also been called Santi Pietro e Marcellino.
Beware -the two churches are often confused.
The Siricius Inscription
The first church here was possibly built by Pope Siricius in the 4th century, close to the Jewish catacombs on the Via Labicana. The evidence for this rests on two marble fragments of separate inscriptions discovered in the foundations of the church. One reads: [..] Natal[..] Sirici[us] + Papa [..] [Ecc]lesiae [..]rique [..]or [..] , and the other: [..]ru[..] proprio fecit. On this evidence it is postulated that the pope consecrated the church himself on the feast day (dies natalis) of the saints, but you can judge for yourself how thin the inference is.
A reference to a titulus for these two saints exists for the year 590, but does not specify a church.
The first certain reference is in the Liber Pontificalis for Pope Gregory III in the 8th century, which reads: Fecit etiam de novo ecclesiam sanctorum Marcellini et Petri prope Lateranum. ("He also built from new the church of saints Marcellinus and Peter near the Lateran"). The de novo is ambiguous, but it certainly means that the edifice was built from scratch even if an older church was demolished in order to do so.
A hospice which became a centre for pilgrims visiting the Lateran was then located here, the Ospedale del Salvatore, but the church seems to have been disused in the 12th century.
The alleged relics of the martyrs Marcellinus and Peter were brought to the church in 1256, and the church was restored again the same year by command of Pope Alexander IV. Twenty years later, the hospice and church were given to the Confraternity of those Commended to the Saviour, so the hospice was still then functioning.
In 1707 Pope Clement XI gave the complex to the Aleppine Antonian monastic order of the Maronites, who established a monastery here for about half a century. They had been founded in 1695. Apparently the monastery did not do well, and the church fell into such disrepair that rebuilding was eventually necessary.
Old church layout
The Nolli map of 1748 shows the old church as having a single nave with an integral semi-circular apse. There were two shallow side chapels near the entrance, and a large external side-chapel abutting on the far right hand side which was entered through an arcade of three arches. The old monastery occupied an L-shaped layout, with one wing to the right of the church façade and the other next to the near right hand side of the church. In the angle of the L was a cloister garden, separated from the Via Labicana by a wall.
The old church did not stand on the site of the present church, but was set back to the south-west and faced onto a very large piazza at the junction of the Via Labicana and the present Via Merulana. The convent premises to the west of the present church has a south wing at an angle to the street wing and to the other side of a courtyard from it, and this occupies the site of the old edifice.
The present church and convent is the result of this rebuilding by Pope Benedict XIV in 1751, whereupon it became a canonry with four canons of the Lateran. As such it was a dependency of the monastery attached to the church of San Pietro in Vincoli.
In 1763 the canons leased the complex to some reformed Carmelite nuns formerly at the (now lost) church of Santa Lucia alle Botteghe Oscure. These were called Teresiane del Corpus Domini, and remained here until 1906. (The reference to "Carmelite friars" in other online sources is a mistake; monache means "nuns".)
Since 1911 this has been a parochial church served by diocesan clergy, after a few intervening years of disuse. The parish was actually established in 1906 after the nuns left, but there seem to have been problems with legalities.
In 2011 the church was attacked by a gang of anarchists during a street demonstration, and while they failed to gain access to the interior they dragged a statue of Our Lady and a crucifix from the priest's house and kicked them to bits in the street. Their remains can be viewed in a kind of shrine near the entrance to the sacristy - on one's right as one enters the church.
The church used to be thought to be the one listed among the tituli as Titulus Nicomedis which was mentioned in a synod in 499. However, this was not universally agreed upon and one alternative opinion was that there was a church of San Nicomede on the Via Nomentana. Revised scholarly opinion is now suspicious of most of the traditional claims linking the ancient tituli with existing churches, as lack of stability on one site is known for some. Nowadays, when a new church is built to replace a temporary one it is always on a separate site to ensure continuity of worship, and the same motivation would have operated in early days.
A titulus for Marcellinus and Peter seems to have been established by Pope Gregory the Great in 590, this being transferred from a lost basilica of Santa Crescenzia in Via Mamertina. The titular priest was recorded as being one Albino. However, the next priest listed after him was Rainiero in 1099, and the "Catalogue of Pietro Mallio" compiled for Pope Alexander III describes the title as attached to Santa Maria Maggiore. This is the evidence for thinking that the church was abandoned in the 12th century until restored in the 13th.
Layout and fabric
The church stands below the present street-level, indicating its ancient foundation. The present building is on a square plan and is almost cube-shaped, the main body of it being slightly lower than it is wide and long. The fabric is rendered in pale orange with the architectural details in white travertine.
The roofline of the church over the façade is higher than the cornice, forming a low attic plinth, and on either side of the pediment it bears a pair of stone flaming urns. Behind these is a pair of tiny lead saucer domes on cylindrical drums and bearing ball finials.
The attractive and rather low main dome is set on a drum with four buttresses and four oeil-de-boeuf windows, and has five steps. Its lantern is tall, with four arched windows separated by volutes and topped by ogee curves. The cap is shaped like an upturned goblet, and supports another ball finial.
The side walls of the church are more simply treated than the façade. The central section of each is recessed, and has a rectangular window high up. The right hand street frontage has contrast between the two pairs of pilasters flanking the recessed section. The pair on the left are Ionic, matching the façade, but the pair on the right have blind capitals.
The entrance façade is embellished in a style close to Neo-Classicism, indicating that the Baroque was becoming unfashionable. It was designed by Girolamo Theodoli, who was an Italian nobleman as well as an architect. He also designed the campanile at Santa Maria dei Miracoli (his best known work is the Teatro Argentina).
The central portion of the façade projects, and has two pairs of gigantic Ionic pilasters in shallow relief flanking the entrance. Another pair of these pilaster strips is folded into the internal corners created by the façade's projection; two more pairs decorate the outer corners of the façade, and the last two are round the corners where the side walls are recessed. These support a massive entablature which runs along the sides of the church, but not round the back where the building abuts onto the former convent. The frieze of this on the façade bears an inscription proclaiming Pope Benedict's rebuilding, and the pediment above the projecting portion contains his coat-of-arms.
The doorway has a simple triangular pediment. There is a central rectangular window below the entablature, the lintel of which intrudes into the architrave.
Layout and fabric
The interior is clearly influenced by the work of Francesco Borromini. It has a Greek cross plan, with the central dome over a crossing off which run four short arms. One is for the entrance, two are side chapels and the fourth is extended by means of a semi-circular apse with conch in order to form the sanctuary.
Overall, the decoration is very simple and is based on a pale blue with architectural elements in white.
The structural piers supporting the pendentives of the dome do not have an interior identity distinct from the walls of the cross arms. Each has a chamfered corner flanked by a pair of Ionic pilasters in shallow relief, which are doubletted along their outer edges. Other Ionic pilasters are folded into the corners of the chapels and entrance bay, a pair flanks the entrance and four occupy the sanctuary. These pilasters support an entablature which runs round the interior of the church. Above it in the entrance and side chapel arms is a large rectangular window, and these three windows provide the natural lighting in the church.
The short vaults of the side arms are undecorated, except for molded borders. The dome pendentives have a chi-rho device within a wreath.
The dome is divided into four sectors by wide rays, and each sector has a wide border. These rays are continued down the sides of the low drum, which has four elliptical windows. The oculus of the dome has a lantern, unusually containing four Doric pilasters as well as a Dove of the Holy Spirit. The oculus is surrounded by a palm leaf wreath.
The conch of the apse matches the dome, being divided into three sectors by similar rays.
The side walls of each cross arm each have a doorway with a marble doorcase incorporating an oversized raised triangular pediment. Above this is a cantoria or corbelled balcony for solo musicians, with balusters in the frontal.
The high altar is set against the curved wall of the apse. Above the entablature over it is a triangular pediment, curved to fit.
The aedicule has no pilasters or columns, but is an elaborate frame for the very large altarpiece executed in red marble. Above the altarpiece, two stucco angels support a cross, accompanied by several winged putto's heads. The composition is crowned by two floating curved cornice fragments flanking the gilded cross. The sides of the altarpiece frame have two gilded hanging garlands.
The altarpiece is by Gaetano Lapis 1751, and depicts the Martyrdom of SS Marcellinus and Peter.
Underneath the mensa of the altar is a porphyry urn containing relics of the catacomb martyr "St Marcia".
The two main side chapels, in the longitudinal cross arms, have identical altar aedicules in red marble. Each has a pair of ribbed Corinthian columns supporting an entablature and pediment.
Next to this chapel is another small chapel, entered through a doorway. This is dedicated to Our Lady of Lourdes. The ceiling was painted by one N. Caselli in 1903, who also executed the depictions of the shrine at Lourdes and the vision of St Bernadette.
The chapel on the left hand side is dedicated to the Blessed Virgin, with a copy of Guido Reni's The Virgin in Glory with Angels, St Joseph and St Teresa at Caprarola.
Next to this chapel is the Chapel of Reconciliation, which contains a copy of Reni's Crucifixion at San Lorenzo in Lucina.
To the left at the entrance is an image of SS Marcellinus and Peter, placed here in 1256, with an inscription recording Pope Alexander IV's restoration of that year.
The church is open (old information, 060608 tourist website 2009):
Daily 7:00 to 12:00, 16:00 to 19:30.
Mass is celebrated, according to the Diocese (June 2018):
Weekdays 7:30 (7:00 in summer), 8:30, 19:00,
Sundays 7:30 (summer only), 8:30, 10:00, 11:00, 12:30 (not summer), 19:00.
This is the station church for the third Saturday of Lent.
The feast of Our Lady of Lourdes, 11 February, is celebrated here with special solemnity.
The patronal feast of the church is that of SS Marcellinus and Peter, on the 2 June (celebrated here first Sunday in June as a solemnity, but in the general Church calendar with an optional memoria). The saints are always celebrated and venerated together.
(The parish has no website.)