André Breton was the founder and chief theorist of the surrealist movement. Through his study of medicine and work with the insane, he became interested in irrational imagery. After serving as a medical auxiliary during the First World War, he discovered the work of Sigmund Freud. The subjects of psychiatry, the illogical and the unconscious mind appealed greatly to the Surrealists. By 1924 Breton had become a prominent figure in the Parisian avant garde and had gathered around him a group of poets and artists interested in exploring the subconscious. The surrealist movement was launched that year with Breton's 'Manifesto of Surrealism'.