to the royalist army. Both sides prepared for the confrontation they knew was coming: Buenos Aires truce and Callao revolt Historian Rufino Blanco Fombona says that "By 1824 Bernardino Rivadavia had made a pact with the Spanish, obstructing the Ayacucho Campaign": on 4 July 1823 Buenos Aires made a truce with Spanish commissionaires (Preliminary Peace Convention (1823)) that required it to send negotiators to other South American governments before it would take effect. It stipulated that hostilities would cease 60 days after its ratification and that the truce would last a year and a half; meanwhile, a definitive peace and friendship would be negotiated. Juan Gregorio de Las Heras met in Salta with Brigadier Baldomero Espartero, but did not reach an agreement. Among other measures taken by the viceroy for containing the imminent rebellion, on 10 January 1824 Casimiro Olañeta was ordered: Rivadavia – who believed that the project would establish peace – paralyzed the authorities of Upper Peru (today's Bolivia), refused assistance, and withdrew the garrisons of advance posts near the border, to the detriment of the cause of the Peruvian patriots. The Irish military historian Daniel Florencio O'Leary was of the opinion that with the truce "Buenos Aires (had) implicitly withdrawn from the struggle", and that "the Buenos Aires Government's pacts with the Spanish, were to the detriment of the American cause". On 1 January 1824, Bolívar fell terribly ill in Pativilca. , plenipotentiary minister of Río de la Plata arrived in Lima, asked Peru to adhere to the truce, but the Peruvian Congress rejected it. Nevertheless, beginning on 4 February 1824, various quarters of Callao mutinied, leading to the whole Argentine infantry of the Expedición Libertadora, together with some Chileans, Peruvians and Colombians (nearly two thousand men) going over to the royalists, raising the Spanish flag and handing over the fortresses of Callao. The mounted grenadier regiment of the Andes also revolted in Lurin on 14 February: two squadrons went over to the Callao to join the mutiny, but when they noticed that they had joined the royalists, a hundred of them, with their regiment commanders, went to Lima to join the independentists. The unit was then reorganized by General Mariano Necochea. In the midst of these events, the minister of Colombia, Joaquín Mosquera "fearing the ruin of our army" asked Bolivar "and what do you plan to do now?". Bolívar, in a decided manner, answered: "Triumph!".