The president, having completed his preparations, began his march from Jauja in good order on the 19th of December 1547, taking the route of Cuzco, and especially desirous of crossing the river Abancay34 in some safe place. In this part of his march he was joined by Pedro de Valdivia, the governor of Chili. Valdivia had come by sea to Lima, on purpose to raise men, and to procure various stores of which he was in want, with clothing and ammunition, on purpose to enable him to proceed in the conquest of Chili. On his arrival at Lima, and learning the situation of affairs in Peru, he determined upon joining the president. His arrival was considered as an indication of good fortune; for, although the president had already in his army many officers of merit and capacity, and of eminent rank and fortune, there was not any one in Peru who possessed so much experience in the manner of conducting warlike operations in that country as Valdivia, on which account he was considered as a fit person to be opposed to the experience and stratagems of Carvajal, who was much dreaded by every one in the presidents army, more especially since the late defeat of Centeno, which was entirely attributed to the talents of Carvajal. About the same time Centeno joined the president with more than thirty horse, who had accompanied him ever since the defeat of Guarina. Continuing his march amid considerable difficulties, owing to the scarcity of provisions, the president at length reached the province of Andahuaylas, where he judged it proper to remain during the winter, on account of the violent rains which fell night and day almost without ceasing, by which the tents were all rotted. The maize which they procured as food for the troops was all wet and spoiled, by which a considerable number of the soldiers were afflicted with dysentery, of which some died, notwithstanding the care taken of the sick by Francisco de la Rocha, a Trinitarian monk, who acted as physician to the army. Although there were above four hundred sick at one time, so great was the care bestowed, that they were as well attended and as plentifully supplied with medicines as if in a populous city, insomuch that they almost all recovered.

The arrival of Valdivia and Centeno diffused much joy through the army, which was expressed in frequent feasts and entertainments, with concerts of music, running at the ring, and similar amusements. During the continuance of the army in winter quarters at Andahuaylas, the general Hinojosa with Alfonzo de Alvarado and Valdivia applied themselves indefatigably to have every thing in the best possible order for taking the field. On the commencement of spring, and when the rains began sensibly to diminish, the army broke up from Andahuaylas and marched to the bridge of Abancay, about twenty leagues from Cuzco, where it halted until bridges were constructed across the Apurimac at the distance of twelve leagues from Cuzco35, as the enemy had broken down all the bridges over that river, and it was necessary either to construct new ones, or to make a circuit of more than seventy leagues to get to Cuzco. On purpose to distract the enemy, the president caused materials for the construction of bridges to be carried to three different points on the Apurimac; one on the great road of the Incas36, a second in the valley of Cotabamba, about twelve leagues farther up the river, and a third still farther up the Apurimac, at a village belonging to Don Pedro de Puertocarrero, where that officer was posted with a hundred men to guard the passage. For the construction of these bridges cables and ropes were prepared, after the manner of the native Peruvians as formerly described in our general account of the country; and beams and pillars were got ready on which to fix the cables when the army should be collected at the intended place of passing the river. Had Gonzalo been able to ascertain the place at which it was intended to pass, he had assuredly opposed the royalists, and would at least have made it exceedingly difficult for them to construct a bridge; but as he could not ascertain the actual point fixed on, he did not consider it safe to divide his force so as to oppose the royalists at the three points of demonstration, and satisfied himself therefore by posting spies at the different places, to bring him immediate notice of the place where the royalists might begin their operations, that he might know where to march to oppose them. But the secret was confined to the knowledge of the president, and the members of his council of war.

When all the materials were in readiness, the army began its march for Cotabamba, at which place it was determined to pass the river. In this march the army had to encounter very considerable difficulties in passing through mountains covered with snow. Several of the captains were of opinion that this was an improper route, and proposed another place almost fifty37, leagues higher up; but Lope Martin, who guarded the pass of Cotabamba, always insisted that the securest passage was to be had at that place. In consequence of this difference of opinion, the president sent Valdivia and three other captains to examine the different places; and on their report that Cotabamba was attended by the least difficulty and danger, that place was fixed upon. When Lope Martin got information that the army approached to Cotabamba, he set to work with the Spaniards and Indians of his detachment, to extend and tighten the cables and ropes across the river, of which the main support of the bridge was to be composed. Three of the cables were already fixed, when the spies employed by Gonzalo came to the place, and cut two of them without resistance. On this intelligence being communicated to the army, it gave much concern to the president and his officers, lest Gonzalo might bring up his forces to dispute the passage before the army could be able to get over. The president, therefore, accompanied by his principal officers, Hinojosa Alvarado and Valdivia, hastened to the scite of the bridge, where he immediately gave orders for some companies of infantry to pass the river on Peruvian flat boats or rafts, which was deemed a very hazardous enterprize, both on account of the rapidity of the current, and because it was believed the enemy might be in some force on the other side. Among the first who got over was Hondegardo with a few soldiers, after whom several other captains of infantry got across with their men, so that before night above four hundred men were got over, some of whom swam over their horses along with the flat boats, holding them by the bridles, and having their musquets and other arms tied to the saddles. Yet so rapid was the current, that above sixty horses were lost on this occasion, either drowned or dashed against the rocks.

On receiving notice from his spies that a part of the royalists had got across the river, Gonzalo sent off Juan d'Acosta with two hundred mounted musqueteers, with orders to give no quarter to any of those who had passed the river, excepting such as had newly come from Spain. On the approach of Acosta, as the royalists then on that side of the river were not numerous, they mounted a considerable number of Indians and negroes on the horses which had been got over, arming them with lances, and by that means presented the appearance of a formidable squadron drawn up on a height, the few Spanish troops who were on that side of the river being placed in the front rank; insomuch that, when Acosta went to reconnoitre, they appeared so numerous that he did not venture to attack; and returned for a reinforcement. In the mean time, the bridge being got ready with the utmost possible diligence, most of the royalists passed the river, every one expressing the utmost astonishment at the negligence of Gonzalo in not being at hand to dispute the passage, as a hundred men at each of the three places where preparations had been made for passing, might have rendered the attempt exceedingly hazardous.