From the arrival of the first Franciscan missionaries, Spanish, Latin, and indigenous languages played parts in the evangelization of Mexico. Many sixteenth-century churchmen studied indigenous languages in order to instruct native peoples in Christian doctrine. The same men also found Castilian and Latin appropriate in certain contexts. All told, there existed a kind of "linguistic coexistence" from the beginning of the colonial period. Some monks and priests attempted to describe and classify indigenous languages with Spanish. Philip II of Spain decreed in 1570 that Nahuatl become the official language of the colonies of New Spain in order to facilitate communication between the natives of the colonies. In 1696 Charles II reversed that policy and banned the use of any languages other than Spanish throughout New Spain. Beginning in the 18th century, decrees ordering the Hispanization of indigenous populations became more numerous and Spanish colonizers no longer learned the indigenous languages. After independence the government initiated an educational system with the primary aim of Hispanization of the native populations. This policy was based on the idea that this would help the indigenous peoples become a more integrated part of the new Mexican nation. Except for the Second Mexican Empire, led by the Habsburg Maximilian I, no Mexican government tried to prevent the loss of indigenous languages during the 19th century. In 1889, Antonio García Cubas estimated that 38% of Mexicans spoke an indigenous language, down from 60% in 1820. By the end of the 20th century, this figure had fallen to 6%. For most of the 20th century successive governments denied native tongues the status of valid languages. Indigenous students were forbidden to speak their native languages in school and were often punished for doing so. In 2002, Mexico's constitution was amended to reinforce the nation's pluricultural nature by giving the State the obligation to protect and nurture the expressions of this diversity. On June 14, 1999, the Council of Writers in Indigenous Languages presented Congress with a document entitled "Suggested legal initiatives towards linguistic rights of indigenous peoples and communities", with the goal of beginning to protect the linguistic rights of indigenous communities. The Ley General de Derechos Lingüísticos de los Pueblos Indígenas was passed in March 2003, establishing a framework for the conservation, nurturing and development of indigenous languages. Critics claim that the law's complexity makes enforcement difficult. Indigenous languages Spanish is the de facto national language spoken by