Existentialism is a concept that became popular during the second World War in France, and just after it. French playrights have often used the stage to express their views, and these views came to surface even during a Nazi occupation. Bernard Shaw got his play "Saint Joan" past the German censors because it appeared to be very Anti-British. French audiences however immediately understood the real meaning of the play, and replaced the British with the Germans. Those sorts of "hidden meanings" were common throughout the period so that plays would be able to pass censorship.
Existentialism proposes that man is full of anxiety and despair with no meaning in his life, just simply existing, until he made decisive choice about his own future. That is the way to achieve dignity as a human being. Existentialists felt that adopting a social or political cause was one way of giving purpose to a life. Sartre is well known for the "Theatre engage" or Theatre 'committed', which is supposedly committed to social and/or political action.
On of the major playwrights during this period was Jean-Paul Sartre. Sartre had been imprisoned in Germany in 1940 but managed to escape, and become one of the leaders of the Existential movement. Other popular playwrights were Albert Camus, and Jean Anouilh. Just like Anouilh, Camus accidentally became the spokesman for the French Underground when he wrote his famous essay, "Le Mythe de Sisyphe" or "The Myth of Sisyphus". Sisyphus was the man condemned by the gods to roll a rock to the top of a mountain, only to have it roll back down again. For Camus, this related heavily to everyday life, and he saw Sisyphus an "absurd" hero, with a pointless existence. Camus felt that it was necessary to wonder what the meaning of life was, and that the human being longed for some sense of clarity in the world, since "if the world were clear, art would not exist". "The Myth of Sisyphus" became a prototype for existentialism in the theatre, and eventually The Theatre of the Absurd.
Right after the Second World War, Paris became the theatre capital of the west, and popularized a new form of surrealistic theatre called "Theatre of the Absurd". Many historians contribute the sudden popularity of absurdism in France to the gruesome revelations of gas chambers and war atrocities coming out of Germany after the war. The main idea of The Theatre of the Absurd was to point out man's helplessness and pointless existence in a world without purpose. As Richard Coe described it "It is the freedom of the slave to crawl east along the deck of a boat going west". Two of the most popular playwrights of this time include Samuel Beckett, who's most famous piece was "Waiting for Godot", and Eugene Ioensco with "Exit the King". Most absurdist plays have no logical plot. The absence of the plot pushes an emphasis on proving the pointless existence of man. Quite often, such plays reveal the human condition at it's absolute worst.
Absurdist playwrites often used such techniques as symbolism, mime, the circus, and the commedia dell'arte, which are quite evident in the more popular plays of the time, such as Waiting for Godot, The Bald Prima Donna, and Amedee.