After the defeat of General Manuel Belgrano in the battle of Vilcapugio, on 1 October 1813, the bulk of the republican Army of the North withdrawn to the east, establishing its headquarters in the town of Macha. Belgrano hoped to reinforce his exhausted and demoralized troops with local draft and supplies. The royalist situation was no better, despite their recent victory. General Joaquin de la Pezuela lost more than 200 men in Vilcapugio, along with a good number of mules and horses, the main way of carrying artillery and other provisions through the rugged soil. A smaller fraction of Belgrano's army retreated to the city Potosí, under the command of General Díaz Vélez. By mid-October, Potosí was threaten from the north by a royalist squadron, led by Colonel Saturnino Castro, who seized t