Notwithstanding every precaution employed by Centeno to conceal his operations and intentions, it was impossible to prevent intelligence from spreading in various directions, more especially after the expedition of Mendoza to Arequipa. Every thing he had already done, even the number of his troops, and of the musquets and horses he had collected, was fully known, by means of Indians and Spaniards who had escaped from La Plata, in spite of the guards which had been set, to watch the passes of the mountains. Alfonso de Toro, who acted as lieutenant governor of Cuzco under Gonzalo Pizarro, happened at this time to be a hundred leagues to the northward of that city, keeping guard in one of the passes of the mountains, as by letters from Gonzalo the viceroy was reported to have gone into the mountainous country, and was supposed to have directed his march by that road toward the south of Peru. On receiving notice of the late revolution at La Plata, De Toro returned in all diligence to Cuzco, where he levied forces to oppose Centeno; and, having assembled the magistrates and principal inhabitants of Cuzco, he informed them of what had occurred at Las Charcas, and as there was a sufficient force in Cuzco to suppress the royalists, he thought it incumbent on him to march to La Plata for that purpose. To gain them over to his purpose, he represented that Centeno had revolted without any just cause, and had usurped authority in Las Charcas for his own private ends, under pretence of serving the king; whereas Gonzalo Pizarro, being actual governor of the kingdom of Peru, ought to be obeyed as such till his majesty sent orders to the contrary. That the revolt of Centeno, being both criminal in itself and contrary to the law, every one was bound to resist him, and to punish his temerity. He recalled to their remembrance, that Gonzalo Pizarro was engaged in serving the general interest of the colonists, to procure the revocation of the obnoxious ordinances, in which common cause he had exposed his fortune and personal safety to every hazard, as it was well known that every inhabitant of Peru would be stripped of his property if the regulations were put in force. That besides the general advantage procured by Gonzalo in setting aside the obnoxious regulations, for which all were infinitely indebted to him, it was obvious that he had not in any respect conducted himself contrary to the royal orders, and had not in any manner set himself against the authority of the sovereign; since, on his arrival at Lima for the purpose of presenting their remonstrances, the judges of the royal audience had already arrested the viceroy and sent him out of the kingdom, of which these judges had appointed Gonzalo interim governor; and that in marching in a warlike manner against the viceroy, he had acted at the request and by the orders of the royal audience; as was manifest by his being accompanied by Cepeda, one of the royal judges and chairman of the audience. He asserted that no person in Peru could take upon him to determine whether the audience had acted right or otherwise in conferring the government on Gonzalo; and that it was the duty of all to support him in that office, till they received the ulterior orders of the sovereign.

At the close of this discourse, every one acknowledged the justice of what he had represented, and voluntarily offered to support Gonzalo with their lives and fortunes; although in reality most of them did so more from fear than good will, as they stood in great awe of De Toro, who had hanged several persons in a summary manner, and had made himself universally dreaded by his cruel and ferocious disposition and conduct, so that no one dared to oppose or contradict him in any thing. After a short deliberation, a set of resolutions were entered into, in which the transactions of Centeno in Las Charcas were recited as seditious and unlawful, and he was declared to have assassinated Francisco de Almendras, the lieutenant governor, to have levied forces in rebellion against the legitimate government, and to have passed the boundaries of the province of Las Charcas in hostile manner; for all which reasons it was just and proper to make war upon him, and to reduce him to obedience. All this was done principally to satisfy or to amuse the people, and to make them believe that the partizans of Gonzalo acted reasonably and lawfully, as all those who signed these resolutions were perfectly aware of the real state of affairs. In reality, although matters were thus represented in the popular assemblages, in justification of the measures of the insurgent party, or at least to excuse their actions under specious pretences, those who took an active part on the present occasion, used often to declare, both in the presence and absence of Gonzalo, that the king would certainly give, or ought to give him the government of Peru, as they were resolved not to receive any other person in that capacity, such being the resolution of Gonzalo in which they all concurred.

Alfonso de Toro now proceeded to levy an army, of which he declared himself captain general and commander in chief, and appointed captains and other officers to command under his authority. In all his proceedings he carried himself with a high hand, employing force and violence, instead of persuasion and good treatment. He protested publickly and with many oaths, that he would hang up every one who did not assist and contribute to the cause; and even had several persons carried to the foot of the gallows, whose lives he was induced to spare by dint of solicitations. He abused and maltreated others, using everyone in the most outrageous manner who did not give way to him in all things. By this violent procedure he completed his warlike preparations at very small expence; insomuch that it appeared afterwards by his accounts, that he had not expended above twenty thousand crowns in this expedition, as he took away gratuitously all the horses that were to be found in Cuzco, and constrained all the inhabitants who were able to carry arms to accompany him in the expedition against Centeno. By these means De Toro collected three hundred men, tolerably armed and equipped, with which he marched from Cuzco to a place named Urcos, about six leagues from that city, where he remained three weeks in anxious expectation of intelligence from Las Charcas: But all the roads and passes between and La Plata, were so well guarded by the Indians, who were entirely disposed to favour Centeno, that he was unable to learn any thing of the movements or intentions of the royalists in Las Charcas, so that he was constrained to remain continually on the alert lest he might have been surprized. Besides these military precautions, he rigorously punished all who presumed to show the slightest disinclination towards the interest of the Pizarrian faction, or to express their sentiments in any respect in disapprobation of his own designs; insomuch that all were constrained from dread of punishment to appear heartily attached to the cause in which he was engaged.

After remaining three weeks encamped at Urcos, he determined to march in search of Centeno, and advanced for that purpose to the village named Del Rey. As the troops of Centeno happened to be a good deal scattered at this time, he was under the necessity of retreating on the approach of De Toro. These hostile chiefs being encamped at the distance of about twelve leagues, entered into a negotiation to endeavour to form an accommodation; but, as they were unable to agree upon any terms, De Toro advanced for the purpose of attacking Centeno; who, on the other hand, was unwilling to risk the chance of an engagement, owing to the inferiority of his force, and because a defeat might have dispirited his own party and have been of great advantage to the cause of the insurgents. On this account he retired in proportion as De Toro advanced, accompanied by a great number of large Peruvian sheep loaded with provisions and ammunition, and carrying along with him all the principal curacas or native chiefs, to prevent De Toro from being able to avail himself of the assistance of the Indians. In this manner Centeno continued to retreat across a desert and uninhabited country of forty leagues extent, till he arrived at a place named Casabindo, through which Diego de Roias had formerly descended from the elevated region of Peru into the eastern plain of the Rio de la Plata. Alfonso de Toro continued the pursuit as far as the city of La Plata, which is an hundred and eighty leagues to the south of Cuzca. Finding that place abandoned and entirely stript of every thing which might contribute to the subsistence of his troops, and being unable to procure provisions on account of the absence of all the curacas or caciques, he was under the necessity to discontinue his pursuit of Centeno, and even found himself compelled to return towards Cuzco. In this retreat, De Toro took the command of the advanced guard of fifty men, ordering the main body to march at leisure, and left a rear-guard of thirty of his best mounted cavalry under Alfonso de Mendoza, with orders to use every possible means of procuring intelligence of the motions of Centeno; that, in case of his following, the troops might be collected together in good order to rejoin the van.