The term Byzantine architecture derives from its being the result of civilization belonging to the ancient city of Byzantium, later re-founded by Constantine in 330 AD and called Constantinople. With the transfer of the capital from Rome to Byzantium and, then, with the subdivision of the Roman empire into the Empire of the East and Empire of the West -395 AD, the Byzantine Empire was developed which lasted until 1453, when Constantinople will fall due to the work of the Turks. Various cultural aspects came together, first of all, that deriving from the Hellenistic tradition to determine the characteristics of this architecture.
In addition to the Hellenistic influences, the Byzantine architectural language will include Syrian, Persian, and Egyptian characters, with the vast areas where this civilization spread. Despite the obvious differences arising from the contacts in the various geographical areas, the Byzantine architecture maintained over time common basic distinctive characteristics. It had a primarily religious nature, intended to ensure the salvation of the spirit for man.
When referring to the production of Byzantine art, one should not think only of the forms expressed in Constantinople and its imperial court, but also of all the widespread work done by monks and hermits scattered throughout the vast empire. Perhaps, also, for this reason, these architectural expressions still maintain a particular charm, which reminds us and makes us feel that man's tension towards God, which is expressed in sacred buildings.
Byzantine architecture is generally divided into several periods. The Paleo-Byzantine period from the 4th to 5th century it was the first period, the so-called "training" period, in which the transition from late ancient culture to the more typical forms took place. Being the Byzantine architecture, essentially, the bearer of religious values will manifest itself primarily in the construction of places of worship, which will be both basilica and central plan. For the latter, the domed structures belonging to the late ancient period will be inspired, deepening, and developing the concepts of spatial unity and emphasizing their centrality.
Compared to the Roman dome roof, which required a continuous circular wall for support, the Byzantine dome will be set on a square base. Circular domes will be built on square plants through the use of four spherical triangles, called "plumes.", generally decorated with naturalistic or anthropomorphic motifs. When the emperor Constantine made Byzantium the new capital of the Eastern Roman Empire, giving it the name of Constantinople, a new architectural style also began to spread.
Initially, the Byzantine architecture did not differ much from the Roman one then, over time, it was influenced by oriental tendencies; for the churches. The Greek cross plan was used, the bricks replaced the stones, the mosaics took over the sculptural decorations, and complex domes were raised.
Byzantine art was therefore born from the fusion of different elements from Greek culture and taste, from Roman power and from the love of the Orientals for ornamentation. While on the one hand, the Romans worked to make the exterior of the architecture pleasing to the eye, the Byzantines undertook to embellish the interior.
Two of the most important structural features of Byzantine architecture are the Greek cross plan and the domes; Santa Sofia in Constantinople and San Marco in Venice, are a characteristic example. On the contrary, the Byzantine churches of Ravenna have preserved the traditional forms of the first paleochristian Roman churches of the 4th and 5th centuries, while the typically Byzantine innovative elements are found only in the structures and decorations.
Other structural elements characteristic of Byzantine sacred architecture are:
the polygonal apse on the outside and semicircular on the inside, the lantern which appears on the outside like a tower and which hides a dome inside and the external decoration with pilasters, hanging arches, and blind arches.
As for the domes, the Romans knew how to build them only as of the roof of a circular space, while the Byzantines found a way to make them on square environments, filling the brick corners that continued the curve of the vault; this happened due to four spherical triangles called plumes.
These domes are characterized by a very accurate building art; the curves support a great weight and strongly resist the pressure towards the outside. The Romans preferred to cover the interior of their buildings with marble or frescoes. The Byzantines otherwise employed rich mosaics, which combined the beauty of marble surfaces with spatial illusions. Due to the golden reverberation, an illusion of continuity was created between the internal space and its mural limits.
The mosaics in the sacred architecture were arranged with particular rigor; it could not have been imagined for Christ a more suitable place than the center of the dome, compared to the celestial vault, nor for the Virgin a more sacred place than the apse basin. The figures of the four Evangelists were often arranged on the four pendentives of the dome because they had to be placed very close to the figure of Christ whose life they had narrated.
At the bottom, on the walls, where they could easily be observed by the faithful, the scenes of Christ's life were represented and, at an even lower level, the more earthly images: the Saints occupied the wall space closest to the ground and consequently more closely linked to everyday life.
In the Iconoclastic era (726-787 and 814-843), sacred images disappeared and were replaced by simple symbols (crosses), animals, birds, or vegetation.
Some causes of Iconoclasm were: the spread of superstitious practices that used images as idols, the desire by the military oligarchies from which the emperors came to limit the preponderant power of the Church. In particular of its monastic component, a supporter of the images, and the contact of large sections of the population with the new occupants of the Middle Eastern area, the Arabs, averse to the anthropomorphic images of the deities.
While the West was always against Iconoclasm, in the East, it had a significant first moment in 726, when Emperor Leo III decided to remove the icon of Christ, which was located above the main door of the imperial palace.
This was followed in 730, the edict prohibiting the worship of sacred images, instead of granting the possibility of producing profane images, such as imperial portraits, battle scenes, and circus scenes.
Thus began the first phase of the iconoclastic struggle, which reached its peak during the reign of Constantine V (741-775). The illuminated icons and codes were destroyed and burned, the figured decorations of the churches erased and replaced with profane motifs such as flowers, animals, architectural scenes, but above all symbols, including that of the cross.
The veneration of the images was reintroduced with the Ecumenical Council convened in Nicea in 787 by the Byzantine empress Irene and her minor son Constantine VI, perhaps also in order to pursue a policy of reconciliation with the West, where the hegemony of Charlemagne.
In the year 815 Emperor Leo V, the Armenian again introduced the ban on venerating sacred images, which will last until 843; this time, however, the actions taken were much less radical, the images were not destroyed, but only covered with white paint, and the private veneration of the icons remained somewhat tolerated.
The definitive re-establishment of the cult of images took place in 843 by the empress Theodora.
Art and artists, often monks, however, were subjected to the strict control of the Church which established once and for all which images could be represented, in what way and in which part of the building of worship they had to be found, in obedience to a rigid hierarchy, from then on always substantially respected. This arrangement saw Christ depicted in the center of the dome, the Virgin in the apsidal basin, flanked by the Archangels and then apostles, prophets, patriarchs and saints who could cover every part of the church. From the stylistic point of view, there was a radical estrangement of the figuration from reality, which had the aim of revealing not the human aspect of the person depicted, but rather his spiritual qualities.