In 1116 Pope Paschal II founded the monastery in the Basilica of Santi Quattro Coronati, which in 1138 was controlled by one of the most powerful Italian Benedictine abbeys: Santa Croce di Sassovivo at Foligno in Umbria. The monastic buildings were located on the left side of the Basilica and underwent an intense phase of development during the 13th. century. The blocked-out windows of the monastic cells are still visible on the imposing western facade that overlooks Via dei Querceti. The cloister, the subject of this restoration project, also dates from the first half of the 13th. century. It is a splendid example of what can be defined as 'cosmatesque' architecture, the name coming from one of the principal sculptor-architect families, the Cosmati, who worked in Rome during the 12th. and 13th. centuries.

The cloister is made up of four corridors supported on the inner side by arches resting on 96 coupled columns and 10 marble pilasters. The corridors were originally covered by a roof. A splendid brick cornice with marble corbels and mosaic intarsia runs the whole length of the four sides. Traditional medieval figurative elements are harmoniously fused with direct references to classical antiquity, such as the fluted pilaster strips. There is clear evidence of the relationship that existed with the cloister at the Abbey of Sassovivo. The latter was being constructed in 1229 and bears the signature of the Roman marble worker Pietro de Maria. It is therefore possible that he is also the author of the Roman cloister.

After the complex was turned into a orphanage for girls run by Augustinian nuns in 1564, restoration and extension work was carried out that also involved the cloister; in particular, the corridors were covered by barrel vaults and a simple open gallery on pilasters was constructed above them. Between the 16th. and 19th. centuries the cloister was seriously tampered with, altering both its aspect and static condition. Between 1912 and 1916 the Fine Arts Superintendent Antonio Muñoz, well known for his interventions on medieval buildings, restored the thirteenth-century part of the cloister and placed a precious marble cantharus, probably from the 11th. century, in the center of the open space that had been turned into a garden.

Muñoz adorned the perimeter walls with notable stone inscriptions and pieces of sculpture, dating from Roman times up to the Middle Ages, which had been found inside the complex. With its controlled space and harmonious proportions, the cloister today represents a typical example of how the stratification of parts of epochs and different styles in the city of Rome has given rise to a single irreplaceable figurative whole. Every day the cloister is open not only to tourists and students interested in its architecture, its works of art and historical testimonies, but also to believers of all creeds who see it as a place of prayer and contemplation.