The document discusses the history and characteristics of Early Christian architecture. It began as Christianity spread throughout the Roman Empire between the 1st and 6th centuries AD. Early Christian architecture was heavily influenced by Roman architectural styles like basilicas. Churches during this period were usually large basilican buildings with an entrance at the west end and an altar facing east. Important examples include St. Peter's Basilica in Rome and churches in Ravenna, Italy decorated with mosaics. Baptisteries and catacombs were also constructed during the Early Christian period. By 600 AD, most Roman villages had their own churches governed by a bishop.