Po-on is the beginning of the Rosales Saga of F. Sionil José – a series of novels about Rosales, Pangasinan in the Philippines. The Rosales Saga has five parts, all of them individual but interrelated novels, composed namely of the following titles in terms of historical chronology: Po-on, Tree, My Brother, My Executioner, The Pretenders, and Mass. Among José's five-part novel series, the Rosales Saga, "Po-on" was the last to be written and published but the first in terms of story-telling chronology.

        In Po-on begins the narration of the experiences of one generation of the Salvador family (later changed to "Samson" to avoid being hunted by the Guardia Civil), through Eustaqio "Istak" Samson, a farmer who joined the fleeing Ilokanos known as the mal vivir or "agraviados". The peasant family reluctantly left their original hometown to escape further oppression and persecution from the colonial authorities. Their journey lead them to a new place at Rosales, Pangasinan, under the care of the wealthy mestizo named Don Jacinto, who despite owning large tracts of land, supports his fellow countrymen and indios in their plight. The novelist discusses the life and the origins of this family while embellished with the historical background of the Philippines during the late 1880s up to the early 1990s.

Reference:https://en.wikipedia.org/wiki/Po-on