Discover Santa Maria in Cosmedin and the Bocca della Verità

The Basilica of Santa Maria in Cosmedin is a minor basilica in the rione of Ripa, dedicated to the Virgin Mary. It was built first in the sixth century as a diaconia — a charitable deaconry — in an area of the city populated by Greek immigrants, and it celebrated Eastern rites. It still does: the church currently serves the Melkite Greek Catholic community of Rome.

It was expanded in the eighth century and renovated in the twelfth, when the campanile was added. A Baroque façade and interior refurbishment of 1718 were removed in 1894–1899: the exterior was restored to twelfth-century form, while the architecture of the interior recalls the eighth century with twelfth-century furnishings.

The narthex contains the Bocca della Verità.

The name is traditionally derived from the Greek kosmidion, from kosmos, meaning ornament or decoration. More recent scholarship connects it instead to the Monastery of Kosmidion in Constantinople, whose monks fled to Rome after the monastery was destroyed in the Avar-Persian siege of 626 and brought the name with them.

Its most interesting feature is a subtraction. A Baroque façade and interior refurbishment of 1718 were removed between 1894 and 1899. The exterior was restored to twelfth-century form; the architecture of the interior now recalls the eighth century, furnished with twelfth-century fittings. Rome normally accumulates; this building was taken backwards on purpose.

The campanile is the landmark. Added in the twelfth-century renovation, seven storeys of brick with arcaded openings — one of the finest Romanesque bell towers in the city, and visible along the Tiber from a considerable distance.

The portico is where the crowd is. The narthex holds the Bocca della Verità against its left wall, which means the famous object is outside the church proper and the queue never enters.

And the ground is older than any of it. The basilica stands on the Forum Boarium, the ancient cattle market, among a complex of temples and shrines to Hercules. Under the crypt is a platform of ancient tufa, tentatively identified as part of the Great Altar of Unconquered Hercules and possibly dating from the sixth century BCE. A later building on the site, probably fourth-century CE, had a colonnaded loggia — either a government food distribution centre or another building of the Hercules complex.

It was built as a charity, in a foreign quarter, on a cattle market. In the sixth and early seventh centuries this stretch of the Tiber developed into a Greek quarter — the schola graeca — populated by Greek, Syrian and Egyptian merchants and by functionaries of the imperial government in Constantinople, during the Byzantine Papacy of 537–752, when the popes were approved by and subject to the Byzantine emperors. The church began as a diaconia: a deaconry for relief of the poor.

Its name arrived as a refugee. The Monastery of Kosmidion stood outside the walls of Constantinople, built under Theodosius II and dedicated to Saints Cosmas and Damian, and functioning as a centre for charitable relief. In 626 it was destroyed in the Avar-Persian siege. Some of its monks fled to Rome, settled in the Ripa Graeca, continued the same charitable work through a diaconia dedicated to the Virgin, and brought the name of their lost house with them. From Rome the name spread to other Byzantine exarchates in Italy — Ravenna, Naples.

Then it was enlarged twice and undressed once. The church was expanded in the eighth century and renovated in the twelfth, when the campanile was added. The Baroque campaign of 1718 gave it a new façade and interior; the restoration of 1894–1899 took both out again.

The oldest work on the site was never built as a church at all. Under the crypt lies a tufa platform that may be part of the Great Altar of Unconquered Hercules, possibly from the sixth century BCE — and the Bocca della Verità in the portico is itself a piece of Roman engineering that arrived here in the thirteenth century from somewhere else.

What are the opening hours? Every day, 9.30 to 17.50. Closed on 1 January.

Is it free? Entry to the basilica is free. Whether a charge is made to photograph the Bocca della Verità is not published by the basilica or by any public authority, so carry a little cash.

Do I have to queue to see the church? No. The Bocca is in the portico, so the queue is outside. You can walk into the basilica without joining it, and it is usually almost empty.

What actually is the Bocca della Verità? An ancient Roman marble mask of about 1,300 kg, probably showing the sea titan Oceanus. Its original purpose is uncertain: possibly a drain cover from the nearby Temple of Hercules Victor, which had an open oculus and so let rain in, or a vent used to drain the blood of cattle sacrificed to Hercules.

Why do people put their hands in it? A medieval legend that it bites the hand of a liar, revived for a global audience by Roman Holiday in 1953.

When did it arrive here? Probably removed from the temple in the thirteenth century and set against the church wall; moved into the portico in the seventeenth.

Why is the church called "Cosmedin"? Traditionally from the Greek kosmidion, meaning ornament. More recent scholarship traces it to the Monastery of Kosmidion outside Constantinople, destroyed in 626, whose monks fled to Rome and brought the name.

What rite is used? The Eastern rite. The basilica serves Rome's Melkite Greek Catholic community, and the Divine Liturgy is on Sundays at 10.30.

Why does it look medieval if it was refurbished in 1718? Because the Baroque façade and interior of 1718 were removed between 1894 and 1899 — the exterior restored to twelfth-century form, the interior to something recalling the eighth.