His early works were not considered surrealist enough to be included in the International Surrealist Exhibition in London in 1936. This sent Bacon into a down spiral causing him to destroy a large number of pieces.
He was unfit to serve in World War II and went back to painting and ended up selling a painting to the MoMA. After this success, Bacon returned to London and painted his first take on Velázquez's Portrait of Pope Innocent X which marked the start of his obsession with male authority figures in his art.
After this point his style evolved. It retained techniques that critics said were reminiscent of old masters in their richness and lines. However it was blended with surrealism.
In 1957 he painted Study for a Portrait of van Gogh V
In this painting it is easier to see how Bacon's style combined traditional techniques with surrealism.
Head of a Man, 1960
Seated Woman, 1961
I appreciate Bacon's sketching style because of his loose lines that translates well to his paintings.
Study for a Portrait of Lucian Freud (sideways), 1971
Untitled (Kneeling Figure), 1982
Each style shift coincides with deaths of Bacon's close friends or family, introductions to new artists, and success or failure of his art exhibitions.
At the end of this progression Bacon had strayed from clear figures. I think that these figures depict something more human. It is more about the movement and flesh than the individual features. Bacon found a way to reduce people to their human essence while extracting their uniqueness that comes from defined traits. I think this is what was so haunting and powerful about his work.
Russell, John. Francis Bacon. New York: Thames and Hudson Inc., 1985. Print.
Bacon/Moore: Flesh and Bone 12 September 2013 to 5 January 2014. Woodbridge: Antique Collectors' Club Ltd. , 2013. Print.
Peppiatt, Michael. Francis Bacon in the 1950s. Norwich: Sainsbury Centre for Visual Arts , 2006. Print.