In the Middle Ages, Santo Stefano Rotondo was in the charge of the Canons of San Giovanni in Laterano, but as time went on it fell into disrepair. In the middle of the 15th century, Flavio Biondo (Flavius Blondus) praised the marble columns, marble-covered walls, and cosmatesque works-of-art of the church, but he added that unfortunately "nowadays Santo Stefano Rotondo has no roof". Blondus claimed that the church was built on the remains of an ancient Temple of Faunus. Excavations in 1969 to 1975 revealed that the building was actually never converted from a pagan temple but was always a church, erected under Constantine I in the first half of the 4th century.