This organization, formally created in the Italian town of Cosio d'Arroscia on July 28, 1957, was born within another protest movement of the 1950s: the Lettrist International, which the founders of the SI, notably Guy Debord (1931–1994), reproached for its inefficiency. The SI is the product of the merger of a series of previous groups of artists and intellectuals, such as the Lettrist International, the International Movement for an Imaginist Bauhaus (MIBI), the CoBrA group (of which Lubertus Jacobus Swaanswijk will be a part) and the London Psychogeographic Committee.

Along with Debord, other Situationist exponents such as Gianfranco Sanguinetti, Asger Jorn, Raoul Vaneigem, Constant Nieuwenhuys, Michèle Bernstein and others participate. After a brief period exclusively devoted to the search for the improvement of art, the Situationists set about refounding a revolutionary theory of the modern world. They criticize at the same time the spectacular-mercantile society of the West and the state capitalism of the East. Close for some time to the group Socialisme ou barbarie, a group in which Guy Debord participated in 1960-61 and the Marxist philosopher Henri Lefebvre, the Situationists became increasingly critical and their actions did not stop intensifying throughout the 1960s, despite the fact that they rarely had more than a dozen members. As a result of the rejection of art and political radicalization, in 1962 a split was organized, at the initiative of seven dissident members who wanted to continue producing art: Nash (brother of Asger Jorn), Fazakerley, Thorsen, De Jong, Elde's Studio, Strid and Hans Peter Zimmer) the so-called Second Situationist International, which however did not prosper. The SI is commonly considered one of the main ideological drivers of the social events that occurred in France in May 1968.

The only pictorial works of the Situationist International are the industrial paintings of Giuseppe Pinot-Gallizio") and the peintures détournées of Asger Jorn.[2]​.

The Situationists are in favor of the establishment of workers' councils and played a key role in the May 1968 revolt, participating in street fighting and associating with the radical anarchist group the Enragés (Iracundos) to occupy the Sorbonne and promote the strike movement in the factories during the decisive day of May 15, 1968.[3] They are present in the Council for the Maintenance of Occupations (CMDO).

After this success (10 million "wild" strikers throughout France), quickly stopped by the lack of influence of the most radical elements on the labor movement controlled by the "Stalinist" unions that dedicated themselves to saving the De Gaulle regime (Grenelle agreements), the Situationists took refuge in Belgium from where they spread the text Enragés et situationnistes dans le mouvement des occupations, an account of their actions during that great revolt. Debord refused to take the position of leader and soon put an end to the Situationist International just at the moment it was reaching its greatest level of fame and when dozens of passive and idealistic "revolutionaries", contemptuously called "pro-situs" by Debord, seduced by the prestige of the SI, sought to join its ranks. Debord took advantage of that moment to clearly explain the urgent need to put an end to the I.S. in a fundamental text for understanding the particularities of the Situationists: La Véritable scission dans l'Internationale Situationniste, published in April 1972.

This organization, formally created in the Italian town of Cosio d'Arroscia on July 28, 1957, was born within another protest movement of the 1950s: the Lettrist International, which the founders of the SI, notably Guy Debord (1931–1994), reproached for its inefficiency. The SI is the product of the merger of a series of previous groups of artists and intellectuals, such as the Lettrist International, the International Movement for an Imaginist Bauhaus (MIBI), the CoBrA group (of which Lubertus Jacobus Swaanswijk will be a part) and the London Psychogeographic Committee.

Along with Debord, other Situationist exponents such as Gianfranco Sanguinetti, Asger Jorn, Raoul Vaneigem, Constant Nieuwenhuys, Michèle Bernstein and others participate. After a brief period exclusively devoted to the search for the improvement of art, the Situationists set about refounding a revolutionary theory of the modern world. They criticize at the same time the spectacular-mercantile society of the West and the state capitalism of the East. Close for some time to the group Socialisme ou barbarie, a group in which Guy Debord participated in 1960-61 and the Marxist philosopher Henri Lefebvre, the Situationists became increasingly critical and their actions did not stop intensifying throughout the 1960s, despite the fact that they rarely had more than a dozen members. As a result of the rejection of art and political radicalization, in 1962 a split was organized, at the initiative of seven dissident members who wanted to continue producing art: Nash (brother of Asger Jorn), Fazakerley, Thorsen, De Jong, Elde's Studio, Strid and Hans Peter Zimmer) the so-called Second Situationist International, which however did not prosper. The SI is commonly considered one of the main ideological drivers of the social events that occurred in France in May 1968.

The only pictorial works of the Situationist International are the industrial paintings of Giuseppe Pinot-Gallizio") and the peintures détournées of Asger Jorn.[2]​.

The Situationists are in favor of the establishment of workers' councils and played a key role in the May 1968 revolt, participating in street fighting and associating with the radical anarchist group the Enragés (Iracundos) to occupy the Sorbonne and promote the strike movement in the factories during the decisive day of May 15, 1968.[3] They are present in the Council for the Maintenance of Occupations (CMDO).

After this success (10 million "wild" strikers throughout France), quickly stopped by the lack of influence of the most radical elements on the labor movement controlled by the "Stalinist" unions that dedicated themselves to saving the De Gaulle regime (Grenelle agreements), the Situationists took refuge in Belgium from where they spread the text Enragés et situationnistes dans le mouvement des occupations, an account of their actions during that great revolt. Debord refused to take the position of leader and soon put an end to the Situationist International just at the moment it was reaching its greatest level of fame and when dozens of passive and idealistic "revolutionaries", contemptuously called "pro-situs" by Debord, seduced by the prestige of the SI, sought to join its ranks. Debord took advantage of that moment to clearly explain the urgent need to put an end to the I.S. in a fundamental text for understanding the particularities of the Situationists: La Véritable scission dans l'Internationale Situationniste, published in April 1972.