structural:expansion
History

It is believed that before the arrival of Christianity in France, a Gallo-Roman temple dedicated to Jupiter stood on the site of Notre-Dame. Evidence for this includes the Pillar of the Boatmen, discovered beneath the cathedral in 1710. In the 4th or 5th century, a large early Christian church, the Cathedral of Saint Étienne, was built on the site, close to the royal palace. The entrance was situated about 40 metres (130 ft) west of the present west front of Notre-Dame, and the apse was located about where the west façade is today. It was roughly half the size of the later Notre-Dame, 70 metres (230 ft) long—and separated into nave and four aisles by marble columns, then decorated with mosaics.

The last church before the cathedral of Notre-Dame was a Romanesque remodeling of Saint-Étienne that, although enlarged and remodeled, was found to be unfit for the growing population of Paris. A baptistery, the Church of Saint-John-le-Rond, built about 452, was located on the north side of the west front of Notre-Dame until the work of Jacques-Germain Soufflot in the 18th century.

In 1160, the Bishop of Paris, Maurice de Sully, decided to build a new and much larger church. He summarily demolished the earlier cathedral and recycled its materials. Sully decided that the new church should be built in the Gothic style, which had been inaugurated at the royal abbey of Saint Denis in the late 1130s.