The artists and influences

In my first post I described how Paul Cezanne became a major influential factor towards the cubist movement pioneered by Picasso and Braque, Cezanne's interest in the conversion/simplification of shapes, emphasis on different perspectives and rejection of the idea that art should be a copy of nature fascinated both Picasso and Braque, therefore encouraging them to begin working on the development of the Cubist movement.

Cezanne was a post-impressionist artist and his early expressionistic works were rather dark and heavy, but became lighter and brighter over time. He was compelled to present outlines of forms so as to show both views from the left and right eyes. Cezanne insisted that art wasn't just natures copy, but rather parallel to it, thus pathing the way to the cubist movement.
He observed and recorded colour variations as well as basic geometric shapes that could be found in nature.
This technique influenced many young painters including Picasso, who referred to Paul Cezanne as "my one and only master; father to us all". Considering Cezanne is seen as the "father of Modern Art", Picasso's quote is more or less correct.

Initially, Picasso was the force and behind the movement and encouraged Braque to move away from Fauvism. Both artists worked in sync during 1908-1909 until the beginning of the first world war, the cubist movement then spread quickly through Paris and Europe.
At first, art critics in Paris weren't as taken to the cubist idea as Picasso and Braque were, they described their work as being "full of little cubes" and "bizarre cubiques".