DEAMBULATORY
A deambulatory (Italian: *deambulatorio* or *peribolo* or *ambulacro*) is generally understood to be an annular corridor that runs around the apse, often continuing the side aisles.
In buildings with a central plan, the deambulatory is located between the perimeter wall and the central space. The church of the Holy Sepulchre in Jerusalem was imitated in circular constructions provided with a deambulatory that encircles the entire perimeter wall of the building. Similarly, in the Mausoleum of Constantina (or church of S. Costanza) in Rome, the deambulatory runs between the outer walls and the twelve pairs of columns that support the arches on which rests the high drum of the dome; the Lateran Baptistery also featured a dome and a vaulted deambulatory arranged in a manner similar to that of S. Costanza. To this same type belong, in Rome, the church of S. Stefano Rotondo and, in Perugia, that of S. Angelo.
As a curvilinear corridor running around the apse, the deambulatory already existed in the earliest basilicas, as seen in the remains of the primitive church at Porto and Parenzo, and in the ruins of the urban basilica of Salona, probably from the 4th century, bordered by a semicircular parapet that ran around the apse. In Rome, in the primitive basilica of S. Maria Maggiore, in S. Giovanni in Laterano, in S. Lorenzo fuori le mura, and in S. Severo in Naples, the deambulatory resulted from the same structure of the open apse with columns and arcades. The same is true of the basilica of S. Felice in Nola, and of the churches of S. Giovanni Maggiore and S. Giorgio Maggiore in Naples. Later, a deambulatory is found in the open apse with arcades of the small basilica of Prata near Avellino, perhaps from the 7th century. In some constructions after the 8th century, the ambulatory developed to such an extent that it appeared as the continuation of the side aisles; in the Carolingian period, S. Martino in Tours featured a deambulatory with radial chapels opening onto II. Perhaps from the 10th century is the apse of S. Stefano in Verona, with a two-tiered ambulatory. A spacious deambulatory is found in the cathedral of Ivrea, built between 969 and 1002. Much later is the peribolos of S. Sofia in Padua, where the apse is entirely open with niches.
During the Romanesque period, this architectural motif was used only sporadically in Italy, while in France it took on complex forms, especially with the opening of radiating chapels onto the deambulatory. In Italy, such chapels are found in the church of the Benedictine abbey of S. Antimo in Tuscany, under foreign influences, and also in S. Maria a Pié di Chienti (Marche), in the S. Trinità in Venosa, in the cathedrals of Acerenza and Aversa, where, however, the deambulatory features ribbed vaults, different from those of deambulatories covered by groin vaults.
In France, the deambulatory is encountered in a large number of Romanesque churches. It is, however, rarely found in the Provençal, German, and Norman schools. Most often, the apsidal chapels open onto the deambulatory, but there are also deambulatories without chapels and chapels that open directly onto the apse without a deambulatory (this arrangement might be traced back to Roman constructions such as the Pantheon and the Nymphaeum of the Villa Liciniana). In the Gothic period, the deambulatory, always highly developed outside Italy, appears frequently here as well; it is found in the Franciscan church of S. Lorenzo Maggiore in Naples, built under French influences, and in S. Francesco in Bologna, which has around the apse a peribolos with nine radial chapels. An apsidal peribolos with radiating chapels is also found in S. Antonio in Padua; the cathedral of Milan also features an apse with a deambulatory.
In churches equipped with a deambulatory and radiating apses, the choir achieves a grand effect, which is further enhanced externally by the arrangement of the various parts and the elegance of the decoration, richer than that of the interior. This is seen in the churches of Notre-Dame-du-Port in Clermont-Ferrand, in the church of Orcival, in S. Saturnino in Toulouse, and others.
After the Gothic period, the deambulatory disappears along with other features of Romanesque and Gothic buildings. In Rome in the 17th century, a deambulatory is found exceptionally in the national Lombard church of SS. Ambrogio e Carlo al Corso, perhaps due to a recollection of the cathedral of Milan.
