Olañeta then ordered an attack of the Upper Peruvian royalists on the constitutionalists in the Peruvian viceroyalty. La Serna changed his plans of going down to the coast to fight Bolívar and sent Jerónimo Valdés with a force of 5,000 veterans to cross the River Desaguadero, which took place on 22 January 1824, in order to drive them to Potosí against his former subordinate "because there are indications of a meditated treason, joining the dissidents of Buenos Aires". "Memorias para la historia de las armas españolas en el Perú" ("Memories for the history of the Spanish armies in Peru") by peninsular official Andrés García Camba (1846) detailed the radical change that the events in Upper Peru produced in the viceroy's defensive plans. After a long campaign in the battles of Tarabuquillo, Sala, Cotagaita, and finally La Lava on 17 August 1824 both royalists forces of Viceroyalty Peru (liberals) and of the provinces of Upper Peru (absolutists) were decimated.