The Katipunan was a Philippine revolutionary society founded by anti-Spanish Filipinos in Manila in 1892, whose primary aim was to gain independence from Spain through revolution. The society was initiated by Filipino patriots Andrés Bonifacio, Teodoro Plata, Ladislao Diwa, and others on the night of July 7, when Filipino writer José Rizal was to be banished to Dapitan. Initially, the Katipunan was a secret organization until its discovery in 1896 that led to the outbreak of the Philippine Revolution.

The word "katipunan", literally meaning 'association', comes from the root word "tipon", a Tagalog word meaning "gather together" or society. Its official revolutionary name is Kataas-taasan, Kagalang-galangang Katipunan ng̃ mg̃á Anak ng̃ Bayan (English: Highest and Most Honorable Society of the Children of the Nation, Spanish: Suprema y Venerable Asociación de los Hijos del Pueblo). The Katipunan is also known by its acronym, K.K.K..

Being a secret organization, its members were subjected to the utmost secrecy and were expected to abide with the rules established by the society. Aspirant applicants were given standard initiation rites to become members of the society. At first, membership in the Katipunan was only open to male Filipinos; later, women were accepted in the society. The Katipunan had its own publication, Kalayaan (Liberty) that had its first and last print on March 1896. Revolutionary ideals and works flourished within the society, and Philippine literature were expanded by some of its prominent members.

Emilio Jacinto y Dizon (December 15, 1875 — April 16, 1899), was a Filipino revolutionary known as the Brains of the Katipunan.

Born in Manila, Jacinto was proficient both in Spanish and Tagalog, but preferred to speak in Spanish. He attended San Juan de Letran College, and later transferred to the University of Santo Tomas to study law. He had Manuel Quezon, Sergio Osmena and Juan Sumulong as classmates. He did not finish college and, at the age of 20, joined the secret society called Katipunan. He became the advisor on fiscal matters and secretary to Andrés Bonifacio. He was later known as Utak ng Katipunan..

Jacinto also wrote for the Katipunan newspaper called Kalayaan. He wrote in the newspaper under the pen name Dimasilaw, and used the alias Pingkian in the Katipunan. Jacinto was the author of the Kartilya ng Katipunan as well.

After Bonifacio's death, Jacinto pressed on the Katipunan's struggle. Like general Mariano Álvarez, he refused to join the forces of general Emilio Aguinaldo, the leader of the Katipunan's Magdalo faction. He contracted malaria and died in Magdalena, Laguna, at the age of 23. His remains were later transferred to the Manila North Cemetery.