What is the name of Picasso's 1907 painting considered a seminal work of proto-Cubism?

Picasso’s 1907 painting considered a seminal work of proto-Cubism was Les Demoiselles d’Avignon.

Painted in Paris in 1907, the monumental oil on canvas shows five women whose bodies and faces are fractured into sharp, angular forms. Picasso rejected conventional perspective and naturalistic anatomy, creating a jarring composition that helped point toward the radical visual language of Cubism.

The painting is often described as proto-Cubist rather than fully developed Cubism. Picasso was still experimenting with influences from Cézanne, Iberian sculpture, and African art, and the work does not display the restrained, analytical structure associated with later Cubist paintings made with Georges Braque.

Its title is also a frequent source of confusion. “Avignon” refers to Carrer d’Avinyó in Barcelona, a street associated with brothels—not the French city of Avignon. The work was first shown publicly in 1916 and entered the Museum of Modern Art’s collection in 1939.