 Complete the following phrase:  The Riograndense Republic, often called the Piratini Republic  or , was a de facto state that seceded from the Empire of Brazil and roughly coincided with the present state of Rio Grande do Sul. It was proclaimed on 11 September 1836, by General Antônio de Sousa Neto, as a direct consequence of the victory obtained by Gaúcho oligarchic forces at the Battle of Seival 1836 during the 