The basilica of Santi Cosma e Damiano is a church in the Roman Forum, parts of which incorporate original Roman buildings. The circular building at the entrance onto the Forum was built in the early 4th century as aRoman temple, thought to have been dedicated to Valerius Romulus, deified son of the emperor Maxentius. The main building was perhaps the library of an imperial forum. It became a church in 527 and contains important but much restored early Christian art, especially in its mosaics. Today it is one of the ancient churches called tituli, of which cardinals are patrons as cardinal-deacons: the current Cardinal Deacon of the Titulus Ss. Cosmae et Damiani is Beniamino Stella.