 A few months after his promotion , in April 1825 , secessionists in Cisplatina rebelled . The United Provinces of the Río de la Plata attempted to annex the province , and in retaliation Brazil declared war , triggering the Cisplatine War . Although Marques de Sousa was living in Rio de Janeiro and enrolled in the Military Academy , he was ordered to return to Montevideo . He was soon named adjutant to Brigadier Sebastião Barreto Pereira Pinto , commander of the 1st Division , which was defending Rio Grande do Sul . Marques de Sousa fought in the unsuccessful Battle of Ituzaingó ( known to Brazilians as the Battle of the Passo do Rosário ) on 20 February 1827 . For his acts of bravery during the ill @-@ fated battle , he was promoted on 20 March to captain , and , on 16 August , he was assigned as adjutant to the now Viscount of Laguna , commander @-@ in @-@ chief of Brazilian land forces in the conflict . Marques de Sousa subsequently fought in the Battle of Camaquã on 28 April and participated in other , smaller skirmishes . 
