Possible construction of the St. Stephen Cathedral
After the Edict of Milan, Christian worship became legal. According to the website for the Notre-Dame Cathedral:
"It became possible to build a first Christian building, presumably on the left bank and perhaps, according to some stories, on the side of the current Val-de-Grâce. In fact, we don't know anything specific about this first cathedral or the following. Excavations were carried out at different times in the eastern part of the Ile de la Cité, where the Notre-Dame Cathedral is now located. They make it possible to think that it existed at its site at the beginning of our era a pagan temple, subsequently replaced by a great Christian basilica with five naves, probably quite similar to the ancient basilicas of Rome or Ravenna, in particular. But we don't know if this Cathedral, dedicated to Saint Stephen, had been raised in the fourth century and would have been redeveloped later or if it dates from the 7Th century with older elements in remploi. A certainty though: This St. Stephen's Cathedral was of very large dimensions."