An important figure in the mid-20th Century avant-garde, he is remembered in the cinema world chiefly for his revolutionary 1951 film Traité de Bave et d'Éternité,[3] while his political writings are seen as foreshadowing the May 1968 movements.

[5] Despite his wealthy upbringing (his father was a successful entrepreneur and serial restaurateur), he left school at age 15, reading extensively at home and doing odd jobs.

[1] In 1944 he began his literary career as an avant-garde art journalist during World War II, shortly after the 23 August coup that saw Romania joining the Allies.

He initially traveled to Italy, where fellow experimental poet Giuseppe Ungaretti gave him a letter of introduction and recommendation under the pseudonym "Isidore Isou" to French writer Jean Paulhan, which made his entry into the literary world of the newly liberated Paris much easier.

[5] Intending a total artistic renewal starting from the most basic elements of writing and visual communication, Isidore Isou, assisted by Gabriel Pommerand, organized the first Lettriste manifestation in Paris, on 8 January 1946.

During the premiere of dadaist and fellow Romanian Tristan Tzara's play La Fuit at the Theatre du Vieux-Colombier,[7] Isou shouted "Dada is dead!

[10] The same year, he also published the first of his works on political theory: Traité d'économie nucléaire: Le soulèvement de la jeunesse (Treatise of Nuclear Economics: Youth Uprising).

[13] Debord quickly became an important figure in the so-called left wing of the Lettrists, which were more politically active and overtly "dedicated to Marxist teachings and the critique of capitalist societies".

[14] In October 1952, while Charlie Chaplin was on an extensive publicity tour for his film Limelight, the Lettrist left wing, led by Debord, disrupted a press conference at the Hôtel Ritz Paris and distributed a pamphlet called "Finis les pieds plats" ("No More Flat Feet!")

[18] It was, nonetheless, celebrated by Cannes jury member Jean Cocteau, who called it "the most beautiful scandal of the entire festival"[3] and handed Isou a hastily concocted "Prix de spectateurs d'avant-garde".

In the early 1950s, one segment of Orson Welles' film journal, which was entitled Le Letrrisme est la Poesie en Vogue, included an interview with Isou and Maurice Lemaître.

In this new form, using means acquired over the course of a decade prior, Lettrist art exerted a profound influence upon the posters, barricades, even designs for clothing in the attempted revolution of 1968.