The undesired outcomes of the Paraguay and Upper Peru campaigns led the Junta to be replaced by an executive Triumvirate in September 1811. This new government decided to promote a new campaign to the Upper Peru with a reorganized Army of the North and appointed José de San Martín, a veteran of the Napoleonic Wars who had recently arrived from Spain, as lieutenant colonel. San Martín was ordered to create the professional and disciplined cavalry unit known as Regiment of Mounted Grenadiers ().