Mexico had thrown off Spanish colonial rule in 1821 and there followed a turbulent century marked by the loss in 1848 of New Mexico, Texas, California, Navada, Utah, Arizona and parts of Colorado and Wyoming to the USA. Twenty years later Napoleon III made his disastrous attempt to take over the country and install the archduke Maximilian as experor (15.41 and see p. 672). By 1910, when the Mexican Revolution began, 90 per cent of the peasants had been dispossessed of their land and were forced to live under an iniquitous system of debt peonage to their oppressive landlords, not all of whom were Mexicans. A decade of civil war ended in 1920 with the election of Alvaro Obregon as president and the installation of a revolutionary nationalist, rather than a full-scale Communist or Socialist, regime. It immediately and actively promoted an ambitious cultural program for which Siqueiros (whose most remarkable works were painted much later) drew up a formal Declaration of Social, Political and Aesthetic Principles in 1922, fro, which the following extract is taken.