Mausoleum of St. Constantia
The Mausoleum of St. Constantia, Emperor Constantine’s daughter, also known as Costantina, built in 340 A.D., is the only surviving and well preserved monument in Rome from the time of Constantine. Part of a monumental complex of buildings, comprehending the imposing ruins of the old Constantinian basilica dedicated to St. Agnes, a Christian girl martyred in the ancient Stadium of Domitian (the actual Piazza Navona), and the 8 century basilica still preserved and dedicated to St. Agnes as well, the mausoleum was supposed to house the mortal remains of Constantia and her sister Elena. The original Constantia’s red porphyry sarcophagus is today displayed in the Vatican Museums, in the Pio-Clementino Museum to be more precise, while the one in the mausoleum is just a copy. After being transformed into a baptistery, the mausoleum became a church in 1254. It shows the classical circle paleo-christian plan: the inside area is composed by a central area covered by a dome and a circular ambulatory with 12 pairs or columns, radially positioned. Despite the several destructions happened through the centuries, the ambulatory shows some of the oldest mosaics in Rome, with geometric designs and Christological allegories (scenes of grape harvesting and vine shoots, referred to Christ’s words “I am the wine, and you are the branches”).