Castelli, after securing the loyalty of the northwestern Provinces to the May Revolution through elections of representatives to the Junta in Buenos Aires, had sent General Antonio González Balcarce into the Upper Peru, but he had been defeated at the battle of Cotagaita on October 27.
Castelli had then sent him reinforcements, leading to the first patriotic victory at the battle of Suipacha, on the margin of the Suipacha river in the Sud Chichas province (Potosí Department, in today Bolivia), which gives Buenos Aires control over the Upper Peru.
The royalist generals Vicente Nieto, Francisco de Paula Sanz and José de Córdoba y Rojas are captured and executed.
