Tucked away next to the Forum, the charming little church of Santi Cosma e Damiano (Saints Cosmas and Damian) is one of Rome’s better kept secrets. The church is dedicated to twin brothers from the eastern Mediterranean, two doctors who were martyred at the end of the 3rd century. Unlike their modern counterparts, the brothers charged no fee for the services they provided. (One of these, allegedly, involved transplanting a black leg onto a white body.) Consequently, Cosmas and Damian have become the patron saints of both doctors and surgeons. The cult of the two doctor-saints became very popular in the middle-ages when the belief grew up that any sick person who slept overnight in the church might be granted a dream leading to a cure.
Santi Cosma e Damiano was one of the first churches to use pagan structures in its design. Dating back to the early 6th century, the church incorporated the so-called Temple of Romulus (4th century CE) and part of the Temple of Peace (1st century CE). The Temple of Romulus was not named after the legendary founder of Rome, but the young son of the emperor Maxentius (r. 306-12), who died in 309 CE. (The temple is now thought by many scholars to have been the Temple of Jupiter Stator.)
The ancient brick wall, to the left of the entrance, once sported the famous Forma Urbis Romae, a monumental map of Rome incised into 150 marble slabs. The map measured 18 by 32 metres and depicted, in detail and to scale, the city of Rome at the beginning of the 3rd century CE. Only ten percent or so of the marble slabs have, so far, been recovered.
Nave
Both the church and the adjacent convent were radically restored and remodelled in the 1630s by Orazio Torriani (1578-1657) and Luigi Arigucci (1575-c.1647), at the behest of Pope Urban VIII (r. 1623-44). The pope was a member of the Barberini family, whose heraldic bees are displayed throughout the church.
Apse
The floor was raised 7 metres (23 feet), three chapels were added to either side of the nave and a new wooden ceiling and high altar were installed. The latter, unfortunately, rather obscures the view of the beautiful early-6th century mosaics in the apse, some of the oldest to have survived in Rome.
Vault
The wooden ceiling, part of Urban VIII's remodelling of the church, was painted by Marco Tullio Montagna (1594-1649). The ornate high altar (1637), which partly obscures the mosaics, was designed by Domenico Castelli (1582-1657); the image of the Virgin and Child dates back to the 13th century.
Santi Cosma e Damiano was originally entered from the Forum, which we can see through the large plate glass window at the back of the church.