Henri Rousseau, also known as Le Douanier Rousseau, was born in the city of Laval in 1844.  He worked as a Paris Customs Officer from 1871 until 1893, when he retired to devote himself to art.  Rousseau was a naïve, or untrained painter, and he learned through experience.  He specialized in landscape painting, making his works with bold and arbitrary colors in a technique called dabbing.  Dabbing creates a visual impression that sometimes looks like a blur of different brush marks of paint.  All of this makes the painting seem to come alive.  In the painting, Ile de la Cité, Rousseau uses the techniques of dabbing, coloration, and light contrast to create a 
painting that has a glow behind it.  The glow behind the large building in the background comes from a fire, and suggests  the destruction of the old city, and  the beginning of a "new Paris."  This glow is the result 
of a blazing fire in the city beyond the Ile de la Cité.  The destruction takes place in  the heart of Paris, in the oldest quarters of the city. The fire's glow also
suggests the mystery that Rousseau saw in the City of Light.