The Modernism is a revolutionary period in the Story of Art; the conventions are forgotten to give way to new inspirations.
Many people think that the Modern period is the same as the Contemporary period, but that's not quite right! The modern era began in the 1870s and finished in the 1950s and left the door open for contemporary artists (which means artists who are still alive).
The starting point: The modern art officially started with the Impressionist movement, and particularly with Edouard Manet who painted the "Dejeuner sur l'herbe" (lunch on the grass), a particular artwork because a naked woman is represented in the middle of dressed men. The characters are represented in a very realistic and modern way, which was against the principles of the Academy (the rules consisted of representing mythic scenes, or classical portraits and landscapes).
The social influence
The notion of modernity also came from the Industrialization; the artists were inspired by the reality which surrounded them and they wanted to represent it as it was. For example, the Gare Saint-Lazare painted by Monet represented the technical improvements and the modernity, the artists became a witness of this era.
Then, more and more artists followed this new trend and avoided the traditional rules of painting defined by the Academy. The artists were now trusting their creativity and sensibility; for example, Vincent Van Gogh avoided those rules, and created his own style.
The Cubism appearance
The huge evolution with new artists as Picasso represented the free approach to creativity. This turning point was called “cubism”. This inspired artists from all around the world.
The Modernism acme: the Surrealism
In the 20th century this negation of the realism was called Surrealism, and was embraced by many artists such as Dali, Miro, Magritte, Picasso again, and others. The Surrealism is based on the absurd. The goal is to let the artist's mind create the artwork without looking for a realistic inspiration. The two world wars were a major source of inspiration concerning the humanity incomprehension, and the world’s absurdity.
The artists became so free and could express their creativity as they want; the major example is Marcel Duchamp with his artwork Fountain: the artist made an urinal as an artwork, and signed and exhibited it. Nowadays, this is considered as one of the most innovative artwork.
The end of the Modernism and the beggining of Contemporary art.
After this, the artistic movements and the evolution began with the Pop Art in 1950, which was the beginning of the contemporary era.