In 1812 Francisco Pelliza served as Lieutenant in the Army of the North commanded by Manuel Belgrano. Under the command of General Belgrano, he participated in the battles Tucuman, Salta, Vilcapugio and Ayohuma. On 14, November 1813, Pelliza was taken prisoner at the Battle of Ayohuma. He was imprisoned until 1820, when he was released in a prisoner exchange by General José de San Martin. In 1821, Pelliza was promoted to Captain, serving in the Escolta de Húsares.