Deodato Arellano was a propagandist and first president of the Katipunan. He was born to Juan de la Cruz and Mamerta de la Cruz on July 26, 1844 in Bulacan. The family changed their name to Arellano in compliance with the Claveria decree of 1849. Arellano studied bookkeeping at the Ateneo Municipal de Manila. He also worked as an assistant clerk at the arsenal of the military's artillery corps. He married Marcelo H. del Pilar’s sister, Hilaria del Pillar, on April 22, 1877, after his first wife, Paula Rivera, died. Along with del Pilar, Arellano was an active Freemason. He also solicited funds for Filipino expatriates in Spain when del Pilar had to flee to Spain, because of allegedly subversive articles that appeared in the Filipino newspaper that del Pilar published, Diariong Tagalog. In 1892, Arellano and other freemasons, like Andrés Bonifacio, joined La Liga Filipina, which was founded by José Rizal upon his return to the country. Arellano was elected the league's secretary, but Rizal was deported to Dapitan island in Mindanao a few days later. A few days after the establishment of the Liga, however, Rizal was arrested and detained at Fort Santiago. On July 7, 1892, Gov. Eulogio Despujol announced his immediate deportation to Dapitan. That same day, at the house of Deodato Arellano at 72 Azcarraga Street, Andres Bonifacio— a Liga member— gathered together Teodoro Plata, Valentin Diaz, Ladislao Diwa, Jose Dizon and Arellano himself to found an underground association, the Katipunan. Its main goal was to attain not mere reforms, but the country's separation from Spain and national independence. On July 7, 1892, when the government announced Rizal's deportation, Arellano and his compatriots founded the Katipunan. He was elected the first president of its Supreme Council. In a secret meeting called in October 1892, Arellano was also declared the first president of the association. As president, he endorsed the laws of the Katipunan formulated by Plata and Diwa. Arellano was very careful about hiring new members for there were too many spies. He did not last in that position, though. Several months later, in February 1893, he was replaced by Roman Basa as Katipunan head on the intervention of Bonifacio, who judged him an ineffectual leader. This was a big mistake for Bonifacio, as Arellano was very cautious upon picking members to join the Katipunan. Nevertheless, despite this personal setback, Arellano dutifully carried on with his work in the movement. While Bonifacio and other members were organizing popular councils in Manila, he himself was organizing provincial councils in Bulacan, thereby fulfilling one of Rizal's aims in founding the Liga. When the revolution broke out in August 1896, Arellano repaired to Bulacan and joined Gregorio del Pilar's brigade, becoming its commissary officer. He fought in the battles in Bulacan during the Philippine-American War, but he contracted tuberculosis in the course of the war and died of the disease while he and his fellow revolutionists were fighting in the Cordillera Mountains. His comrades buried him in the town cemetery of La Trinidad, Benguet.
