Brains of the Katipunan. Born in Trozo, Manila, on December 15, 1875. He joined the Katipunan in 1894 and became Bonifacio's trusted friend and adviser. He wrote the Kartilya ng Katipunan, the primer of the Katipunan which embodied the teachings of the organization. He founded and edited the Katipunan newspaper, Kalayaan, whose first issue came out in January 1896. Died on April 16, 1899. He was one of the heroic figures in Philippine history.