I remember reading once that the reason that churches were designed in the shape of the cross was not initially as a reference to the Crucifixion, but because Roman Army Barracks were the first churches by decree of the state.
It referenced the idea that the congregation was akin to lines of soldiers sleeping areas, with the altar being the area reserved for the General (who later took on the role of priest/bishop in the outer colonies for the new state religion), and the two wings were the armory and pantry for the army.
Thus, as the state needed to consolidate its empire with its new religion, they simply turned all barracks into churches, and the form 'stuck' through history thereafter.
I cannot for the life of me remember where I heard this, and I can't find it anywhere on the internet, so I figured someone out here can help clear this up for me.
Simply put: No, church architecture was almost certainly not inspired by Roman Barracks. There are some very broad misconceptions this assumption. First of all the history of church architecture starts long before Christianity became anything like a state religion in the Roman Empire. The earliest church building known to archaeologists is the so-called house church at Dura Europos in Syria from the middle of the 3rd century A.D., when Christianity was still viewed with suspition by the state. At that point church buildings were nothing more than slightly modified private houses. Where congregations were larger the buildings might have been a little more elaborate. When Constantine started to sponsor the Christian Church from 312 on it still wasn't a state religion but only recognised as legal. One of the first church buildings Constantine funded, the Old St. Peter's Basilica at Rome already had a somewhat cruciform design with its large transept at the western end. Later buildings like the church of the Holy Apostles at Milan from the later 4th century or Qalʿat Simʿan in Syria from the 5th century would go even further with the adoption of the cross-shape. They most likely did this for obvious reasons: the huge symbolic importance of the cross as the instrument of Christ's execution.
Secondly late-antique church architecture was hugely diverse. Right from the beginning there wasn't only one type of church buildings. Many belonged to the basilica-type that incorporated elements of Roman civic and probably palatial architecture. Examples would be the already mentioned Old St. Peter's or S. Sabina in Rome. Others like S. Lorenzo in Milan looked nothing like that. There was much room for creativity and regional variety.
Thirdly even after Christianity had become more or less the state religion of the Roman Empire at the end of the 4th century the military and clerical hierarchy were kept very much seperated. A military commander simply wouldn't act simultaneously as a bishop. And military architecture wouldn't at all look like a church because the soldiers weren't sleeping all in one large hall together with their general.
Basically there is pretty much nothing that would corroborate this theory.
See for example: Richard Krautheimer, Early Christian and Byzantine Architecture (Harmondsworth 1986, 4th. ed.)
No, church architecture was inspired by the basilica, which was the Roman building for business and legal matters (like where court cases were judged). The idea of a Christian basilica being, it was the place where God sat in judgment of his people. It was the most convenient and available building archetype Christians thought to use once they became legitimated and had state support.
The cross shape, or transept, was a later medieval addition to the basilica design, starting from the Romanesque period onward (there might be a few eastern and merovingian exceptions to this though, but to the best of my knowledge not many). Carolingian basilicas still tended to adhere to the straight Roman basilica design, although with additions like westworks.
I have not heard before the argument of church architecture inspired by barracks, as barracks were mostly functional (places for the soldiers to sleep) and did not need the elaborate spatial arrangements of basilicas, which were special built to promote a sense of awe.
If this argument were true, that they simply turned all the barracks into churches, then Christianity would've began its spread on the Roman frontier, where the troops were stationed. The fact that Christianity spread primarily from the cities, would seem to refute that idea.
I would likely disregard that conjecture, where ever its source.
Source:
