Santa Costanza is a 4th-century church in Rome on the Via Nomentana. It is a round building with well preserved original layout and mosaics. The building survives in its original form with an ambulatory surrounding a central dome. The mosaics decorating the vault of the ambulatory and the apses of the chapels off the ambulatory are important examples of Early Christian art. The mosaic decoration in the dome no longer survives.

The late 4th-century mosaics in the apses of the chapels off the ambulatory represent the Christian subject of "Traditio Legis" (Christ giving the Law to St Paul) and "Traditio Clavium" (Christ giving the keys to St Peter. The motifs of the decoration on the vault of the ambulatory are similar to those in Late Roman profane mosaics.

Preview	Picture Data	Info
	View of the ambulatory 354-60 Photo Santa Costanza, Rome
	Traditio Legis 4th century Mosaic Santa Costanza, Rome
	Traditio Legis (detail) 4th century Mosaic Santa Costanza, Rome
	Traditio Clavium 4th century Mosaic Santa Costanza, Rome
	Traditio Clavium 4th century Mosaic Santa Costanza, Rome
	Traditio Clavium 4th century Mosaic Santa Costanza, Rome
	Mosaic decoration 4th century Mosaic Santa Costanza, Rome
	Traditio Clavium (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome
	Vault decoration (detail) 4th century Mosaic Santa Costanza, Rome