José de San Martín was defeated by the Luso-Brazilian armies, his allies Estanislao López and Francisco Ramírez continued hostilities against Buenos Aires for its inactivity against the invasion. Pueyrredón called the Army of the Andes and the Army of the North (led by Belgrano) to aid Buenos Aires in the conflict. Guido noted to San Martín that if both armies did that, the north of Argentina and Chile would be easily reconquered by the royalists. San Martín also knew that most of the soldiers of the Army of the Andes would not be willing to aid Buenos Aires in the civil war, as most
Army of the North a victory at Utarango but was later defeated on 12 February by the San Juan river. Rondeau received an order to retreat to Tucumán. The army, almost beaten, marched for nine months going through Potosí and Humahuaca until reaching Tucumán. On 7 August 1816 at Trancas, Rondeau was replaced again by Manuel Belgrano. Martín Miguel de Güemes was named commander of the northern border. Belgrano moved the army to the citadel built by San Martín in the city of Tucumán. There he attempted to rebuild the morale, and materials, in search for a new action in Upper Peru, combining with