Plan of half of the mosaic cupola of Santa Costanza, 1690s
Artist: Pietro Santi Bartoli
© RIBA Library Drawings and Archives Collections
Mosaics provided a luxurious finish on anything from floors to vaults. Rome's great bath complexes, basilicas and other public buildings were a riot of coloured glass mosaics. A few splendid examples remain from the late Roman Empire in Rome and Ravenna, their survival associated with their depiction of Christian rather than pagan subject matter.
This drawing records the mosaic ceiling decoration from the church of Santa Costanza outside Rome. The bold use of exaggerated colour provided the necessary contrast to see the mosaic inside the dark church. The bricks rendered behind the coloured tiles reveal the extensive decay of the mosaic by the late 17th century, signally its fragility and adding to the romance of the drawing. Today, the mosaic no longer remains in the church and this image has become invaluable as a record of ancient Roman mosaics.