Emperor Constantine I had a very busy rule which created marked changes to architectural history. Constantine ordered the construction of the first (Old) St. Peter’s Basilica in Rome which we touched on last week, and then moved his capital to Constantinople (it had been named Byzantium … nothing subtle about renaming his new capitol after himself) around a decade later and began what would eventually become the Byzantine Empire sixty-five years later.
Initially, eastern Christian architecture matched the basilica style imported from Rome during Constantine’s reign. However, with the importations of artistic styles from Asia Minor and Syria, the eastern architecture altered.
The Latin cross style of the basilicas was filled in at the corners and evened out, to form three equally spaced naves divided into three each, forming a square of nine spaces. The rooflines of the spaces became the space-defining factor. The central space nearly invariably featured a large dome, generally with four other domes around it. The exact placement of the four domes varied. They were sometimes placed on the major aisles to form the four arms of the cross, a true cross-in-square design such as Saint Mark’s Cathedral in Venice (which despite being in Italy, had significant trade influence in Byzantine areas). The other approach was to arch the major aisles and then place smaller domes on the corner extremities in a style called quincunx.
The decorating of these churches varied drastically, depending on whether iconoclasm (simply put: abolition of icon usage, the nuances are many and beyond the scope of this article) was an impact or not. The general square shape of Byzantian churches remained consistent throughout the empire’s history. The style had peaked early, in the form of Hagia Sophia, and was never quite rivaled in uniqueness throughout the Byzantine Empire.
The Hagia Sophia was built during the reign of Justinian, a couple of generations after Constantine had built a (predictably) basilica in the same place. In a rare instance for the time, the architects’ names were recorded as Anthemius and Isidorus. The combination of basilica and cross-in-square styles sets Hagia Sophia apart in Byzantine architecture and the sheer size marked it as the largest cathedral built for a thousand years, until Sevilla Cathedral.
The Hagia Sophia is an optical illusion incarnate, the plan is technically just barely off square; but from inside, the building looks very much like a rectangle. The central nave takes up more of the space than would later be norm for a cross-in-square, while semidomes to the east and west of the dome prolong the roofline, with the lower rooflines of the side aisles in sharp contrast. Semidomes were rarely used over the main spaces in future designs, although they became quite familiar over apses — including in buildings still in use today.
Byzantine architecture opted for square designs, while the western Roman style went long — ultimately the styles would blend and mix as trade grew and the world became smaller. St. Marks Cathedral in Venice is an early example of styles merging, as it carries marked Byzantine themes only 300 hundred miles from the Roman heartland of western Christianity.
Sources:
https://www.britannica.com/art/Western-architecture/The-Iconoclastic-Age-726-843
https://www.britannica.com/technology/cross-in-square-plan
https://www.hisour.com/history-of-byzantine-domes-32092/
