The Basilica of Sant'Ambrogio (St. Ambrose) is a church in Milan, northern Italy. One of the most ancient churches in Milan, it was built by St. Ambrose in 379-386, in an area where numerous martyrs of the Roman persecutions had been buried. The first name of the church was in fact Basilica Martyrum.
In the centuries after its construction, the edifice underwent several restorations and partial reconstructions, assuming the current appearance in the 12th Century, when it was rebuilt in the Romanesque style. Initially, the basilica was outside the city of Milan, but over the following centuries, the city grew up around it. It became a center of religious life and a community of canons developed in the church. In 789, a monastery was established within the basilica grounds. The Canons, however, retained their own community and identity instead of fading away. Two, separate, distinct religious communities shared the basilica. In the 11th Century, the canons adopted orders and became Canons Regular. There were now two separate monastic orders following different rules living in the basilica. The canons were in the northern building, the cloister of the canons, while the monks were in the two southern buildings. The two towers symbolize the division in the basilica. The 9th Century dei Monaci ("of the Monks") tower was used by the monks to call the faithful to the monks' mass. The monks supported themselves, partly, from the offerings given after mass. However, the canons didn't have a bell tower and were not allowed to ring bells until they finished their own tower in the 12th Century.
The monastery and church became a large landholder in northern Italy and into what is now the Swiss Canton of Ticino. In August 1943 the Anglo-American bombings heavily damaged the Basilica, in particular the apse and surrounding area. As a result of this a new and remarkably unsuccessful building, now painted pink, was constructed to house the Abbott's offices and the museum. The original edifice, like the great churches of Rome of the same epoch, belonged to the basilica type; it consisted of a central nave lighted from the clerestory, two side aisles, an apse, and an atrium. Investigations made in 1864 have established the fact that the nave and the aisles of the existing basilica correspond with those of the primitive church; the atrium, however, which dates from the ninth century, and two smaller apses, flanking a new central apse of greater depth than the original, were erected. The altar occupies about the same place as in the time of St. Ambrose, and the columns of the ciborium over the altar appear never to have been disturbed; they still rest on the original pavement.
In the following centuries the edifice underwent several restorations and partial reconstructions, assuming the current appearance in the 12th Century. The basilica plan of the original edifice was maintained, with an apse and two aisles, all with apses, and a portico with elegant arches supported by semicolumns and pilasters preceding the entrance. The latter was used to house the catechumens who attended part of the Mass prior to receiving baptism (this custom disappeared in the early 11th century). The current building was begun around 1080. The nave dates to about 1128 and the rib vaults of the nave are from about 1140. Entrance to the church is through an arcaded atrium. The basilica has a semi-circular apse, and smaller, semi-circular chapels at the end of the aisles and no transept. There are galleries over the aisles which support the vaults but preclude clerestory windows. The flat appearance of the hut-like façade is typical of Lombard medieval architecture.
It has two loggias, the lower one with three arches of equal dimensions joining the portico. The upper loggia has five arches of different height that follow the ceiling. It is used by the bishop of Milan to bless the people attending outside. The basilica has two bell towers. The right one, called dei Monaci ("of the Monks"), is from the 9th century and has a severe appearance. The left and higher one dates to 1144, the last two floors added in 1889. The interior of the basilica has the same size as the external portico. Notable is the heavily restored apse mosaic, portraying the Christ Pantokrator and dating from the early 13th century. There are mosaics of about 470 in the oratory of San Vittore in Ciel d'Oro. The church also houses the tomb of Emperor Louis II, who died in Lombardy in 875.