An Incredible Illustration of Ancient Roman Construction The Pantheon Following Louis XV's commitment of respecting St. Geneviève should he survive a severe illness; the church of St. Geneviève was built on the site of what has since become the Panthéon. It was required until 1791 to finish the building due to the enormous amount of funds required to meet the monarch's every whim and imagination. The Revolution had been taking place in the meanwhile. It was given the name "Panthéon" when it was secularized at the time of the French Revolution with a dedication to the memory of prominent Frenchmen. Its layout emphasized the trend of Neoclassical architecture towards the use of classical elements of architecture in a manner that followed completely rationale. The Pantheon is a rectangular structure with a high roofing over the point of convergence and lower hemispheric sphere-shaped forms above the forur arms of the crossing.