Before Emperor Constantine, Christianity lived as a underground religion such as they used churches in basements and underground catacomb cemeteries for ritual meeting places. After, Rome Empire accepted official religion Christianity, this attitude of churches similarly continued and kind of opposite style of imperial regime architectural design. So early Christian churches appeared modest and unassuming.
Roman Empire broke into many fragments between 4th and 6th centuries. The papacy was the most powerful institution of Rome and sponsored the last expressions of classical architecture with the great churches. On the other hand, in Milan struggled between different interpretations of Christianity led to significantly different solutions for church architecture. Political power fight between papacy and imperial regime, created uncertainty in the empire. So Rome acquired some magnificent facilities. For example The Baths of Caralla which was magnificent in terms of scale, technique and decoration thermal complexes. Also The Baths of Caralla is UNESCO World Heritage Site.
Emperor Diocletian (284-305) made drastic effort to salvage the empire’s disintegrating structure. In 294, he proposed a four-man executive system with two young emperors. In theory, two older emperors would retire after ten years and allow to take power their younger’s. Diocletian retired in 305 and he lived in Spalato palace. Spalato was called ‘little palace’ which located near modern Split, Crotia. Palace had three different side entry gates flanked by octagonal guard towers. Spatial organization of little palace created by two intersecting streets divided the palace into quarters. They were lined with colonnades which was not classical tradition. Also architects inserted an arch into the pediment between two central columns which created fastigium, a stage-ish space for imperial appearances. Similar attitude with Hellenistic style which was propylon at temple of Zeus in Lebanon. General sense of Spalato palace, predominantly defensive appearance of Diocletian’s palace set the precedent for the fortified castle of medieval Europe.
In the 300, Constantine rebuilt his father’s capital of Trier in Germany. Constantine was one of the son tetrach. (the four co-emperors of the Roman Empire) Constantine redesigned the city such as erecting new city walls, built one of the largest bath complexes outside of Rome, a formidable basilica side by side with imperial palace etc. Basilica of Constantine served as an audience hall and also like throne room. Heat system used similar with baths. Constantine’s basilica covered in plaster which produced a stern architectural character which influenced the later centuries also.
Maxentius was also one of the son tetrach and Constantine’s chief rival. Maxentius has a quiet different approach of basilica in Rome. Maxentius’s basilica was one of the grandest vaulted concrete structure in world. Maxentius campaign was also different than Constantine, he sponsored excessive patronage of public projects for his claim to power. He restored The Senate House and The Temple of Venus and built a new hippodrome attached to his palace.
Rivarly between Constantine and Maxentius, resulted with battle of Milvian Bridge. Constantine won the battle by help of sympathies of Christian religion. As a result of battle, everything was changed in Christian world. Constantine rewarded with Arch of Constantine in 315. They redesigned and depicted to Constantine even reliefs. So this recycle fragments which called as a Spolia affect other monuments too. Spolia was repurposing of building stone for new construction or the reuse of decorative sculpture on new monuments. As a result of Spolia, conveyed an organic continuity with greatness of Rome.
Emperor Constantine built Rome’s first imperially sponsored church which was St. John’s in the Lateran. Position of this cathedral significantly designed, turned its back on imperial core to avoid conflicts with Roman shrines in the forum district. St. Johns church a very ordinary exterior rather than colonnaded facade. As a general manner of urbanism, the layout system of Lateran followed a five-aisle (a passage between the lines of seats in a plane) (like coridor-ish) longitudinal plan. The architects avoided typological associations with Pegan temples with using the basilica as meeting hall like Constantine works in Trier. Additionally, rounded arches became a standard element of church interiors.
Constantine sponsored the most important church Old St. Peter’s located near the Vatican Hill. This church served as a funereal basilica around the tom of Peter who was the first pope. Old St. Peter’s was like all of the early churches had an assuming facade and one entered a grand colonnaded atrium that focused on a monumental bronze pinecone fountain of 2nd century. At the end of the court, Narthex served as a vestibule (a small closed area) between the atrium and the church interior. The 100 columns did spolia from other monuments like in St. John’s.
Constantine was donating the building to Jesus. ”Because under your guidance the world rose triumphant to the skies, Constantine, himself a victor, built you this hall.”