Santa Costanza, Rome

Santa Costanza is an imperial mausoleum in Rome that was later dedicated as a church (in Italian it is known both as Mausoleo di Santa Costanza and Chiesa di Santa Costanza). This fascinating and beautiful building dates from the 4th century AD and features some of the earliest surviving Christian art.


History of Santa Costanza

The Mausoleum of Santa Costanza is named for Constantine the Great's daughter Constantia (also known as Constantina or Costanza), but the latest scholarship suggests it was actually built for her sister Helena, who died in 360-61.

Early accounts (such as the Liber Pontificalis) record that Constantine built a funerary hall here on the imperial estate at the request of Constantia - this is the long building now in ruins next to the mausoleum. The funerary hall was dedicated to the virgin martyr St. Agnes and resembled others built by Constantine in this period.

The early accounts also report that Constantine built a baptistery on the site, in which both Constantia and Constantine's sister were baptized by Pope Sylvester (314-35).

Construction on the funerary hall and baptistery likely began after 326 (Constantine's last visit to Rome) and must have been completed by 329-330 (the death of Constantine's sister, who is known to have been baptized there).

It was long assumed that the existing mausoleum is this baptistery, but excavations beneath its north end in 1992 revealed a triconch (clover-shaped) building that is a more likely candidate.

After Constantia died in 354, her body was brought back from Bithynia to be buried on the imperial estate in Rome (Ammianus, History 14.11.6).

It was long thought she was buried in the mausoleum, but new data indicates the building was probably still unfinished at that time. So she was probably buried either in the baptistery or in the apse of the funerary hall.

The round mausoleum that survives today was probably built in the 360s or 370s, based on the combination of pagan and Christian elements in the mosaics.

Despite its name, the mausoleum of Santa Costanza was probably built especially for Constantia's younger sister Helena, who was married to the emperor Julian the Apostate (ruled 361-63). As the daughter, sister and wife of successive emperors, Helena had considerable status, so it makes sense she would receive a burial place of great splendor.

Helena is known to have died in 360 or 361 in Gaul and, like Constantia, her body was brought to the imperial estate here in Rome for burial. Helena was buried in the mausoleum and Constantia's body was transferred from its original resting place to the new mausoleum.

Pope Nicholas I celebrated Mass in the mausoleum in 865, when the building was first called Santa Costanza.

The mausoleum became a church in the 13th century. Pope Alessandro IV took what were believed to be Constantia's remains from the main sarcophagus, placed them beneath a central altar, and consecrated the building in her honor on March 12, 1256.

The Mausoleo di Santa Costanza has been periodically restored over the years, but it remains primarily a 4th-century structure. One major restoration took place in 1620 under Cardinal Veralli, during which the mosaics in the dome were sadly destroyed.

In 1992, excavations were carried out beneath the atrium, revealing new information about its early history (as outlined above).

What to See at Santa Costanza

The 4th-century mausoleum of St. Costanza is a round brick building with a small west porch. The building originally had a forceps-shaped atrium at its entrance and an external colonnaded ambulatory (traces of which can be seen in the piazza).

Inside, there is a simple altar under a central dome. The central area is surrounded by 12 pairs of Roman columns, which form a barrel-vaulted ambulatory around the outside. Originally, the walls were covered in marble.

Directly opposite the entrance, at the east side of the mausoleum, is a large niche containing a sarcophagus, decorated with reliefs of putti harvesting grapes (a common theme in classical art). This is a replica of the grand porphyry original that is now in the Vatican Museums, moved there around 1785. It was probably commissioned by Emperor Julian for his wife Helena. Constantia's tomb is believed to be the tub-shaped porphyry sarcophagus now in the left transept of St. Peter's Basilica, moved there in 1606.

The main highlight of Santa Costanza is the barrel vaulting of the ambulatory, which is covered in original 4th-century mosaics. As in the original dome mosaics, these display a fascinating mix of pagan and Christian symbolism and imagery. According to the scholar G. Mackie, Santa Costanza's art reflects "the emerging iconography of the Christian faith in its first years of legitimacy in the Roman Empire."1 The Rough Guide to Italy similarly comments that Santa Costanza "perhaps more than any other building in Rome illustrates the transition from the pagan to Christian city in its decorative and architectural features."2

Dating from the 360s or 370s, the ambulatory mosaics were designed in corresponding pairs leading towards the niche with the sarcophagus, where the flanking mosaic pair is the most elaborate. The pair by the entrance are a simple, geometric design; this is following by a pair with a circular motif with animals and figures. Next are scenes of grape harvesting, then roundels with a leaf design, busts and figures. The pair by the sarcophagus have branches, amphorae and peacocks. The imagery is capable of both pagan and Christian interpretation, which is representative of Constantine's religious policy.

In the east niche above the sarcophagus are the remains of a mosaic with black stars on a white ground and traces of a gold Chi-Rho. The north and south niches bear mosaics dating from either the 5th or the 7th century. They have been poorly restored, but their richly decorated border reveal the quality of the originals. The date and interpretation of these two mosaics have been the subject of much scholarly debate.

The south niche mosaic (left from the entrance) depicts the Traditio Clavium, in which Christ Pantocrator, seated on a globe, hands over the keys to the kingdom of Heaven to St. Peter (Matthew 16:9).

The north niche, on the right from the entrance, represents the Traditio Legis, in which St. Peter receives the right to govern on earth. Wearing golden robes and standing on the hill of paradise, Christ hands Peter a scroll that is inscribed DOMINVS PACEM DAT, "The Lord gives peace through his rule," but may have originally read DOMINVS LEGEM DAT, "The Lord gives his Law." St. Paul stands on the left side of the scene.

The dome mosaics, now destroyed, are known from 16th- and 17th-century paintings: they depicted New Testament scenes behind a golden screen of Bacchic imagery beyond the river Styx. A 16th-century antiquarian also reported seeing mosaics of two seated saintly women, which supports the theory that this mausoleum housed the bodies of both Constantia and Helena. Today, the dome bears faded 17th- and 18th-century paintings.

The funerary hall (c. 330) now lies in ruins in a garden adjacent to the mausoleum, which it is fenced and not possible to enter. However, descending the hill to Piazza Annibaliano provides a clear view of the west end, where the outer wall survives to its full height.

It is similar in layout to the other funerary halls built by Constantine in Rome, such as St. Peter's, San Sebastiano and San Lorenzo. This one was dedicated to St. Agnes (who is honored in a nearby church) and was about 120 meters long. In the chancel area are the remains of an apse area, where Constantia may have originally been buried.

Quick Facts on Santa Costanza

Site Information
Names:Chiesa di Santa Costanza · Mausoleo di Santa Costanza · Mausoleum of Santa Costanza · Santa Costanza
Categories:churches; mausolea
Dedication: St. Constantia (not actually a saint)
Dates:c. 360
Status: active
Visitor and Contact Information
Coordinates:41.922604° N, 12.517354° E
Address:Rome, Italy
Hours:Mon 9-12; Tue-Sat: 9-12, 4-6; Sun: 4-6pm
Lodging:View hotels near Santa Costanza
Note: This information was accurate when first published and we do our best to keep it updated, but details such as opening hours and prices can change without notice. To avoid disappointment, please check with the site directly before making a special trip.


  1. Personal visit (July 19, 2006).
  2. Matilda Webb, The Churches and Catacombs of Early Christian Rome: A Comprehensive Guide (Sussex Academic Press, 2001).
  3. Rough Guide to Italy, 7th edition (2005), 761-62.
  4. Jeffrey Spier, ed., Picturing the Bible: The Earliest Christian Art (Yale University Press, 2007), 95-96.
  5. Marilyn Stokstad, Medieval Art, 2nd ed. (Westview Press, 2004), 26-27.
  6. G. Mackie, "A new look at the patronage of Santa Costanza, Rome," Byzantion 67 (1997): 383-406.

More Information

Bird's eye view of the Mausoleo di Santa Costanza (right) and the ruins of Constantine's funerary hall, where... ©
Exterior view of Santa Costanza. ©
View of the altar area under the dome, decorated for a wedding. Santa Costanza is a very popular wedding venue... © Holly Hayes
© Holly Hayes
© Holly Hayes
Scenes of grape harvesting, a common theme in pagan art, with a bust of a woman, probably Constantina or... © Holly Hayes
The second mosaic panel on the left from the entrance is a circular motif with animals and human figures. © Holly Hayes
The mosaics become increasingly elaborate near the sarcophagus niche at the east end: this panel in the south... © Holly Hayes
Mosaic panel nearest to the sarcophagus in the south ambulatory. It is an elaborate design, featuring... © Holly Hayes
Mosaic in the main niche in the south ambulatory, dating from either the 5th or the 7th century. It has been... © Holly Hayes
The north niche mosaic, dating from either the 5th or the 7th century and poorly restored, depicts the © Holly Hayes
Replica of the main sarcophagus of the mausoleum, which is believed to be that of Helena (d.360/61),... © Holly Hayes
Detail of the original porphyry sarcophagus of Helena, Constantine's daughter, on display in the Pio... © Holly Hayes
View of the altar area under the dome, decorated for a wedding. Santa Costanza is a very popular wedding venue... © Holly Hayes

Map of Santa Costanza, Rome

Below is a location map and aerial view of Santa Costanza. Using the buttons on the left (or the wheel on your mouse), you can zoom in for a closer look, or zoom out to get your bearings. To move around, click and drag the map with your mouse.