Hollywood era
After the Spanish Civil War Buñuel emigrated to the United States. After working in the film archives of the Museum of Modern Art in New York, Buñuel moved to Hollywood to capitalize on the short-lived fad of producing completely new foreign-language versions of hit films for sales abroad. After Buñuel worked on a few Spanish-language remakes, the industry turned instead to simple re-dubbing of dialogue.

Mexican era
Buñuel arrived in Mexico in 1946 at the age of 46, and, despite having previously had no interest whatsoever in Latin America, ended up getting Mexican citizenship in 1949. The first film he directed there was the Gran Casino (1946), produced by Oscar Dancigiers. Buñuel found the plot rather boring and it was not hugely successful. He later again collaberated with Dancigiers in creating El Gran Calavera (1949), an unpretentious but highly successful film starring Fernando Soler. As Buñuel himself has stated, he learned the techniques of directing and editing while shooting El Gran Calavera.

Its success at the box-office encouraged Dancigiers to accept the production of a more ambitious film for which Buñuel, apart from writing the script, had complete freedom to direct. The result was his critically acclaimed Los Olvidados (1950), a masterpiece of urban surrealism (and recently considered by UNESCO as part of the world's cultural heritage). Los Olvidados (and its triumph at Cannes) made Buñuel an instant world celebrity and the most important Spanish-speaking film director in the world.

Buñuel spent most of his later life in Mexico, where he directed 21 films. Some of them are masterpieces of world cinema, and were highly acclaimed, specially in European festivals. Among them we find:

Él (1952)

Ensayo de un crimen (The Criminal Life of Archibaldo de la Cruz) (1955)

Nazarín (1958) (based on the novel by Benito Perez-Galdos, and adapted by Buñuel to the colonial Mexican context)
Viridiana (1961) (coproduction Mexico-Spain and winner at Cannes)

El Ángel Exterminador (The Exterminating Angel) (1962)

Simón del Desierto (Simon of the Desert) (1965).

French Era
After the golden age of the Mexican film industry was over, Buñuel started to work in France along with producer Serge Silberman. During this "French Period" Buñuel directed some of his best-known works: Belle de Jour, Cet obscur objet du désir (That Obscure Object of Desire), and The Discreet Charm of the Bourgeoisie - as well as some equally brilliant but lesser-known films such as The Phantom of Liberty and The Milky Way.

After the release of Cet obscur objet du désir (1977) he retired from film making, and wrote an autobiography, which provides a rather amusing account of Buñuel's interesting life, friends, and family as well as a good representation of his eccentric personality. In it he recounts bizarre dreams, interesting encounters with many well known artists, actors, and writers such as Picasso and Charlie Chaplin, and antics such as dressing up as a nun and walking around town. As one might deduce from these rather blasphemous antics, Buñuel was famous for his atheism. Near the end of his life when he was asked if he a was still an atheist he replied, "Thank god I'm still an atheist."

He married Jeanne Rucar in a town hall in Paris in 1934 and they remained married throughout his life. His sons are film-maker Rafael Buñuel and Juan Luis Buñuel.

He died in Mexico City in 1983 of cirrhosis of the liver.

Surrealism
Famous are his scenes where chickens populate nightmares, women grow beards, and aspiring saints are desired by luscious women. Even in the many mediocre movies he made for hire (rather than for his own creative reasons), such as Susana, Robinson Crusoe, and The Great Madcap, he always added his trademark of genuinely disturbing and surreal images. Running through his own brilliant films is a backbone of devoted surrealism; Buñuel's world is one in which an entire dinner party suddenly finds themselves inexplicably unable to leave the room and go home, a bad dream hands a man a letter which he brings to the doctor the next day, and where the devil, if unable to tempt a saint with a pretty girl, will fly him to a disco. Un Chien Andalou is often hailed as a great surrealist work, but much less is said about The Phantom of Liberty, made nearly 50 years later and every bit as surreal, a true masterwork of a filmmaker at his peak.

Buñuel kept the faith longer than any other surrealist in any medium, and true to those roots, he never explained or promoted his work. On one occasion, when his son was interviewed about The Exterminating Angel, Buñuel instructed him to give facetious answers; for example, when asked about the presence of a bear in the socialites' house, Buñuel fils claimed it was because his father liked bears. Similarly, the several repeated scenes in the film were explained as having been put there to increase the running time. As a result, Buñuel remains little-known, and is often totally misunderstood.

Religious influence
Many of his films were openly critical of middle class morals and organised religion, mocking the pretension and hypocrisy of the Church in ways that are often (then and now) mistaken for vicious and anti-clerical. Many of his most (in)famous films became the target of priggish fury:

L'Age D'Or - a bishop is thrown out a window

Simon Of The Desert - the devil tempts the saint by taking the form of a naughty, bare-breasted little girl singing and showing off her legs

Nazarin - the pious lead character is a fool who wreaks ruin through his attempts at charity

Viridiana - a well-meaning but self-regarding young nun tries unsuccessfully to help the poor

The Milky Way - Two men travel the ancient pilgrimage road to Santiago, Spain and meet enbodiments of various heresies along the way. One dreams of anarchists shooting the Pope.

Buñuel was a lifelong atheist, whose early disillusionment with the corruption of organized religion remained with him for life and spurred him to expose it fiercely in his films.

The story of the making of Viridiana is illustrative. In 1960 Buñuel's earlier Spanish and French films were still known and respected - Un Chien Andalou, L'Age D'Or, and Las Hurdes. Spain, at the time, had virtually no film industry and very little arts activity going on at all, due to years of civil war and the flight of many artists and dissidents from Franco's Spain. As a result, Buñuel was revered in Spain far out of proportion to the number of people who had actually seen his films. Accordingly, Franco decided to approach Buñuel about returning to Spain to make a government-subsidized film.

Buñuel, much to the shock and anger of his friends and other Spanish expatriates, agreed. He submitted the script of Viridiana to the Spanish censors, and despite making most of the changes requested by the Board of Censorship, Viridiana was banned in Spain. Nevertheless it was sent to Cannes where it won the prestigious Palme D'Or. The next day, calls and communications started pouring in, first from the Vatican, with outrage at the Spanish government's production and submission to Cannes of what was seen to be a highly blasphemous film. Buñuel, untouched by the scandal, went home to Mexico, having made the film he wanted and having received acknowledgement for it.

Filming style and technique
Buñuel's style of directing was extremely economical. He shot films in a few weeks, never deviating from his script and shooting in order as much as possible to minimize editing time. He told actors as little as possible, and limited his directions mostly to physical movements ("move to the right", "walk down the hall and go through that door", etc.). He often refused to answer actor's questions and was known to simply turn off his hearing aid on the set; though difficult at the time, many actors who worked with him acknowledged later that his approach made for fresh and excellent performances.