CONTRASFRONTE. – A general term for the masonry structure designed to counterbalance thrusts in vaulted architectural systems. Probably originating in Persian architecture (the earliest example being the palace of Fauruz Abid, perhaps from the 4th century B.C.), contrafforti were also known to the Romans, who employed them in thermal buildings (the so-called Temple of Minerva Medica, the Baths of Diocletian, where they take the form of towers).
In the centrally planned churches of Ravenna (e.g., S. Vitale), contrafforti appear as corner buttresses. However, the first basilican structure in which they are adopted is presumably S. Babia in Milan (late 10th century) to support the double arches that form the framework of the barrel vault. It should be noted, though, that attempts in this direction had already been made in the 9th century in some churches near Oviedo in Asturias.
Another important example from the 10th century is the church of St-Remi in Reims, France, where contrafforti support the roofs of both the central and lateral naves, thus forming a double tier of resistant structures.
But it was only when groin vaults were definitively adopted for the nave roofs that the contrafforte became common in northern Italy and throughout central and western Europe; often it is stepped in profile, or terminates in columns that engage the cornice, or finally is conceived in architectural form, as a pier or half-column extending the full height (late 12th century).
In this latter period, they are also frequently found on façades to counter the thrust of the nave-dividing arches, especially in Lombard churches, but also in those of Emilia and Normandy.
In Gothic architecture, contrafforti sometimes take the form of massive semicylindrical towers extending the full height of the building (S. Francesco in Assisi), or revert to the stepped profile, but with a more dynamic outline; a later refinement consists in separating the function of the lower portion, which acts as a footing, from that of the upper portion, which merely carries load (cathedral of Sées), thus limiting the towers to the height of the vault springing (duomo of Orvieto).
In the 14th century, decoration was extended to the surface of the contrafforti, terminating them vertically with pinnacles and statues, a practice that continued into the following century (duomo of Milan, Certosa of Pavia). Generally, in three-aisled Gothic churches, contrafforti are associated with flying buttresses that transfer the thrust of the groin vaults of the central nave above them. Yet even as late as the mid-15th century and into the next, Rome saw the use of contrafforti composed of solid walls (S. Agostino, S. Trinità dei Monti), which in the 16th and 17th centuries were rationalized into large volutes, especially in churches with elliptical plans (S. Giacomo in Augusta, S. Andrea al Quirinale, S. Annunziata in Parma, S. Maria della Salute in Venice), while the 18th century adopted robust towers for the same purpose (S. Celso e Giuliano in Rome, the sanctuary of Vicoforte).