French New Wave
Whilst France was under under occupation by the Nazis during WWII, the screening of American movies was illegal. When the war was over, French cinemas were flooded with films by directors such as Alfred Hitchcock, John Ford and Orson Welles, and they were consumed eagerly by French film critics. In 1951, the film journal Cahiers du Cinéma was established. The authors of this journal - including Francois Truffaut, Jean-Luc Godard, Jacques Rivette, Claude Chabrol and Eric Rohmer - would watch each of the films by one of the aforementioned directors, and identify common themes and stylistic choices within their opuses (for example, the recurring theme of an innocent man on the run in Hitckcock's films). Based on this, Truffaut published the article "Une certaine tendance du cinéma français" ("A certain tendency in French cinema") in Cahiers in 1954; in which he argued that, although films are generally made by huge teams of people (producers, screenwriters, cameramen, costumers, ETC...), the influence of the director generally overshadows that of everyone else. In other words, the director of a film can be considered its auteur (Author). Thus was born auteur theory, which Truffaut and the others called "politique des auteurs."
In addition to this, these critics writing in Cahiers tended not to look too fondly on the movies the French had been making since the end of the war - feeling that they were predictable and formulaic; referring to them as cinéma de papa (Dad's cinema).
These critics wanted movies that played with narrative conventions and defied audience expectations. Thus, they decided to try their own hands at directing, and thus, the French New Wave began. In 1958, Chabrol made what is debatably the first film of the movement; Le Beau Serge. That one was a bit of sleeper, however. It was with Truffaut's The 400 Blows (1959), Alain Resnais' Hiroshima mon amour (1959) and Godard's Breathless (1960), each of them a critical smash, that the movement really took off.