by Frances Toor which piqued public interest in Posada. Posada's skeletons and skulls, rooted in pre-Hispanic religious ritual, were later adapted by Rivera, Frida Kahlo, O'Higgins, and many others, and are now icons acknowledged worldwide as being at the heart of Mexican popular art and handcrafts. Charlot himself was much interested in and also started avant-garde woodcut. After the Mexican Revolution (1910–1917), post-revolutionary governments sought to educate the public on the principles of social justice, as consecrated in the new constitution. Mural painting became an extraordinary visual vehicle, for occupying public spaces like government buildings, schools and markets where it was accessible to all people and spoke even to the illiterate, in contrast to traditional easel painting aimed at private art consumption by the educated. During the government of President Alvaro Obregon (1921–1924) mural painting was actively promoted by Minister of Education Jose Vasconcelos. Diego Rivera's strong personality and political connections led to many important early commissions. His first commission from Vasconcelos was to paint a mural in the Preparatory School, where four young artists dared to accept Vasconcelos' challenge. Jean Charlot was one of them, and also his friend and roommate Fernando Leal who invited him to get involved. Charlot's fresco Massacre in the Templo Mayor (1921–1922), depicting the massacre in the Great Temple of Tenochtitlan, is in front of Fernando Leal's The Dancers of Chalma (1921–1923). In his fresco Charlot portrayed himself, Leal and Diego Rivera. Charlot's was the first mural finished and the first in the fresco technique. Thus, Charlot participated in the founding of Mexican muralism. The next project Rivera took on was in the Court of Labor at the Ministry of Education building; other young artists, including Charlot, Xavier Guerrero, and Amado de la Cueva, were assigned walls in the Court of Fiestas in the same building. Charlot considered it a first attempt at "communal painting". Rivera, however, eventually wrested control of the project, acquiring more space for himself and recasting the other artists in the role of assistants, even painting over one of Charlot's finished murals, Danza de los Listones (Dance of the Ribbons) to create room for his own Market Place. According to John Charlot, son of Jean, in the beginning only younger artists dared to undertake commissions for large mural paintings. While Vasconcelos himself preferred non-political allegorical works, he carefully avoided guiding the artists, who increasingly became more political in reflecting the