After Constantine passed the Edict of Milan in 313 CE, he supplied Christianity with its first public places of worship. Due to the worshiping style of Christianity, they required large spaces where many people could worship at once. Constantine therefore appropriated several ancient Roman law-courts known as basilicas to house the new religion. This gave Christianity more than just space, it allowed the new religion to emerge literally from underground and establish themselves as a religion here to stay. The community nature of Christianity required a larger space for worship than the temples of Rome. Giving early Christian leaders the basilica was also a powerful statement, as Constantine was essentially allowing them to worship in the local town hall. It was a very public affirmation of Imperial support, as well as the dedicatory inscription on Constantine’s Triumphal arch.
The floor plan of a typical basilica style church enables us to view the standard feature of a basilica style church and recognize the features that carry over to the more elaborate churches of later centuries. The plan allowed for the long, dramatic nave, and the heart of the church to be located at the transept. Additional side aisles were added later, as the number of pilgrims visiting the holy relics inside the church increased during the Medieval Period.
The addition of the atrium was a vital part in the early stages of Christianity, when only those who had been baptized were allowed to enter the holy space of the Church. In the atrium, people could still gather to listen to sermons. For this reason, a baptistery was also required. The baptistery is typically a small circular chamber located just outside the holy space church. The need for both these features eventually faded out, as the population was largely converted to Christianity.