Well, at the 52 B.C. Roman conquering of the Paris basin, it was already an important crossroads between river and road travel (a place where a major north-south route crossed the Seine river across its central island), but it is not certain that the area was the major habitation then (the nearest known major Celtic population centre was in today's Sens). Anyway, the Romans took an interest Paris' island it for its strategic position for a garrison and lightly fortified it, but when it later become a trading centre, Gallo-Roman growth spread to the Left Bank.
I compound that student led prayers violate the first amendment because of the following reasons;The constitution guarantees freedoms of worship for everyone. In such prayers, not all students subscribe to the student faith. Those students are thus offended, and have their rights limited.
The USA constitution does not establish any religion as the official religion and separates the church and the state. public prayers in public gatherings goes against this spirit as it seeks to establish one religion dominance over the other and over the secularist of the state.