Cultural roots lay in the colonial era, but the struggle for Independence and the trauma of establishing a viable national, sovereign state, accounted for the early significance of historiography in Mexico. Bustamante, Alamán, Mora and others put down the strong foundations for a tradition what would later include Justo Sierra during the Díaz era. Although European influences and models remained powerful, the search for an authentic Mexican cultural expression had already begun with the novels of Lizardi and Inclán and the descriptive writings of Prieto. Altamirano after 1867 argued for a national tradition, which was also expressed on writings by Riva Palacio and Payno. Delgado became the first outstanding novelist, with Frías and Gamboa his pre-Revolutionary contemporaries. This was the period of the poetry of Othón, López Velarde, and Díaz Mirón. The Revolution of the 1910s and its subsequent upheaval led to the novels of Azuela and Guzman, but also to the strong reaction to the nationalism engendered by it. The novels of Agustín Yáñez and Juan Rulfo expressed the social and psychological impact of revolution and civil conflict. Octavio Paz and Carlos Fuentes reflected the search for a specific Mexican identity and subject matter. Music, art and architecture modelled contemporary styles on roots deep in the past. Mexican cinema flourished in the 1930s and 1940, but only revived again from the 1980s with its own international figures.