8. EARLY CHRISTIAN ARCHITECTURE IN THE ROMAN EMPIRE UNTIL THE PRINCIPLES OF THE KINGDOM OF JUSTINIAN IN BYZANTIUM

In 298 AD Diocletian divided the Roman Empire into eastern and western. In the following centuries, northern people moved to its territories. Thus, in the period 490-526 AD. the movement of the Visigoths to France and their passage to Spain took place . They also came to the Balkan Peninsula, settled in Bulgaria and descended to the Peloponnese. The Ostrogoths, on the other hand, were Christian Arians. They settled in Northern Italy and Ravenna, which became a major school of architecture in the Middle Ages in the West.

The Mausoleum of Gala Placidia (420-430 AD) was built in Ravenna during this period. It was a martyrdom with a cross-shaped plan. The building was made of thick bricks. A tower-like structure was erected at the intersection of its antennas. There were arches on its outer surface. Its square core was housed in a spherical dome.

St Apollinaire the newer was built in Ravenna in 490. This is a key-monument to the amazing coexistence of the decoration and the building’s shell. The building had a skylight with monolithic windows. The arc inside it is later and specifically it was made during the renaissance.

On the south wall of the building there was a mosaic representation with the theme of Theodoric with his accompaniment offering gifts to the throne Christ (500-525 AD).

On the norht wall of the church there was a mosaic with the theme of the queen and her entourage offering gifts to the Virgin who was holding baby Jesus (500-526 AD).

These mosaics were later replaced by others, which have the following themes: In the south a procession of men-martyrs is depicted while in the north a procession of women-martyrs exists. The figures move towards east. The figures of the processions are depicted starting their route from the palace of Theodoric.

In 536 AD the mausoleum of Theodoric was built. This refers to the mausoleums of the Appian Way in Rome. Its floor plan is a cruciform building, as well as the mausoleum of Gala Placidia. There are pavilions high up. Externally there are deep arches.

The corbels that appear externally on the upper level reveal the pre-existence of an external arc at this level as well.

The dome is monolithic. Some openings, high in the building, were used to raise the monolithic dome higher in the building.

Theodoric Palace dates back to the same period. On the ground floor it had a portico while on the first floor it had a balcony with arched openings.

In the 4th century AD. Junius villa in Cartagena is also dated.

During the second half of the 5th AD. century Neon established the baptistery of the Orthodox. It is octagonal with small arches. Inside it has excellent mosaics. The construction is covered with a dome, the transition to which is made through an octagon.

In the baptistery of the Arians of the same period there was a transition from the octagon to the hemispherical dome.

During the time period 521-532 AD. San Vitale of Ravenna was built. According to historian Choizy, there has never been such harmony as that of this temple. This is internally and externally octagonal.

Inside, the pillars form seven platforms. High up there are vestibules and even higher a dome (triple internal structure). The section of the temple is similar to that of the basilicas but lacks the linear character. The temple narthex is eccentrically positioned.

The temple is made of bricks. Its windows are inscribed in arch drums.

The exterior of the building expresses its internal structure. In this way the floor plan of the building is also read externally. Small supports, which look like exterior, are very important for the stability of the building.

For the first time, in San Vitale, a scalable building volume is presented. The chapels of the temple are independent.

Internally, there is marble up to the height of the vault. After that level there is a mosaic decoration.

The inner niches of the building have a height of two floors and are covered with quadrangular domes.

In the mosaics of the niches, the owner of the church and San Vitale, on either side of Christ and two angels, are presented.

The capitals of the temple are tectonic (like lace). There are suffixes that receive the loads of the bows over them.

To the left and right of the sanctuary arch there are two amazing mosaics. On the left there are Justinian with his entourage and on the right there are Theodora with her entourage. It is the last time that the lords are depicted in the main temple and in their secular attire. Later they were depicted in the narthexes of the temples (eg in the Hagia Sophia of Constantinople).

The dome of the temple is made of hollow plinths.

In 608/609 AD or, according to others, in 615 or 626 AD. The church of Santa Euphemia was created in Constantinople, after the conversion of the palace of Antiochus. It is a temple with an octagonal, concentric plan with an arched niche on each side.

In the period 524-527 AD. Anicia Juliana built St. Polyefktos, which was an octagonal temple with a gallery. It had Sassanid influences. After the destruction of the temple, in the 9th AD. century, its elements were transferred to St. Mark's Piazza.

During the time of Justinian, the so-called Pax Byzantina prevailed. Historian Procopius (500-565 AD), in his treatise "On Buildings" (6 books) mentions the buildings that were built at that time but also those that were built earlier, during the reign of Justin, because he believes that behind them was also Justinian. The Justinian Code contributed to the construction of the buildings of this period, for sure.

The church of Saints Sergius and Bacchus in Constantinople (527-536 AD) has an octagonal core but a cubic external shape. Its inner niches are covered with quarter spheres.

At the level of the ground floor there is an ionic entablature. On the second level there are arches. That is, the vertical elements are interrupted by the entablatures.

In this point, it has to be mentioned that the vertical axis of the temples of the east (eg Sergius and Bacchus) is less pronounced than that of the temples of the west (eg San Vitale in Ravenna).

The temple is covered with 16 spherical sections.

On the outside, the struts are interesting. The building’s strange external shape is due to a failure during construction.

In 537 AD the famous Hagia Sophia of Constantinople was built, which is a basilica with a dome. The diameter of its dome is equal to 100 Byzantine feet. In this temple there was an effort  to cover a large, elongated space. Its vaulting had to cover three large external parts: a central core and two parts on either side of it.

The construction of the temple took place from 532 to 537 AD. and its inauguration took place on December 27, 537 AD, on the day of the feast of St. Stephen.