Rome gave its name to what architecture historians call "Romanesque" - derived from its ancient vaults and rounded arches - but the city has few pure examples (St. Maria in Aracoeli, the Cloister of St. Lorenzo fuori le Mura, the Gallery atop the apse of Ss. Giovanni e Paolo Martiri) of that specific style. As for Gothic - pointed arches, groin vaults and stained glass windows - there is only one such church (the interior of St. Maria sopra Minerva) in Rome

From the 11C to the 14C those fancy styles flourished throughout the North and also to the South, but Rome was then too poor and too politically unstable to rival the stone marvels of Italy's great city states.

On the other hand, Rome had seen a flurry of fine churches in the 4C and 5C (for example St. Sabina), and some between 8C and 9C (for example St. Agnese fuori le Mura), which represent the cream of "Early Christian Architecture." Emperor Constantine launched that movement, legalizing Christianity in 313 and providing vast edifices for Romans to worship Christ just outside the imperial city (“fuori le mura”). They took the name Basilica from the great public halls and meeting places that the Emperor and his predecessors had built to glorify Rome's center. And these churches imitated the grandiose but simple Basilica form: long central area under a high roof (“nave”), with at one end a semicircular bay (“apse”) while at the other end the entrance gates were covered with a porch (“portico”).

The larger churches also had one or two aisles parelleling the Nave on either sides of it and a transept running crosswise between the nave and the apse to form a cross. The other form Rome's early churches followed was the imperial mausoleum, resulting in round churches and baptistries.

Fine churches were built in the 12C and 13C during a revival of building in Rome, but they tended to follow the Basilica model rather than the Lombard or Romanesque style as it was practiced elsewhere.