Did you know the Panthéon was raised thanks to king Louis XV? Indeed, he fell ill in Metz in 1744, and almost died. He prayed for Geneviève, patron saint of Paris: if she save him, he swears to raise a church in her honour! Louis, of course, was cured. He remembered his vow... and decided to rebuild the church of Sainte-Geneviève in 1754. He asked the architect Soufflot for that.
Soufflot, in a place located on Sainte-Geneviève's mountain, put up the Panthéon, in 1770, in Greek style. He wanted to "gather the lightness of Gothic architecture with the magnificence of Greek architecture." Is that all?
No sooner the church was completed, in April 1791, the Constituent Assembly suggested to the city to convert the new building into a "temple dedicated to famous men", in order to put their ashes in here. They wanted to bury here Mirabeau and carved these words on the pediment: aux grands hommes la patrie reconnaissante, "the Fatherland thanks all this great men". The Assembly liked this sentence a lot! And they chose the name "Panthéon"...