Matisse made several views of Notre Dame cathedral from his quai Saint-Michel studio in 1914. In February his friend Marcel Sembat wrote about two views the artist had completed, one "very beautiful", the other "lopsided", which "no one would understand immediately" but he preferred. Matisse reworked features of this canvas before covering almost the entire surface in blue. He left early compositional elements visible beneath the paint, accentuating the temporal quality of building a work of art over time.
from Matisse: Radical Invention, 1913-1917, July 18–October 11, 2010