Before they could reach Gamarra, he had retreated from Jauja and Pasco with 600 of Aldao's men, by the pass of Oyuna, where his men dispersed. Carratala remained watching the pass, while Valdés and Ricafort returned by Canta to Lima; but were so harassed on the march by Vidal's guerillas, that an entire company of light infantry were taken prisoners, and Ricafort, badly wounded, was carried into Lima on a stretcher.
It was then that Arenales marched from Huara on his second expedition to the Highlands. The purpose of this expedition was to hasten the evacuation of Lima and to occupy such positions as would prevent the Royalists from re-establishing themselves in the Highlands; then to open communications at lea with another expedition, which was sent along the coast southwards under Miller. For the first of these purposes the guerillas, guarding the passes from Lima, were instructed to obey all orders received from Arenales. In case of disaster, Arenales was instructed to retire on the reserve stationed at Huaylas.
The division of Arenales consisted of 2,200 men, the column under Miller of 600, thus San Martin was left with about 3,000 sick and convalescent in front of the Royalist Army of 7,000.
The troops sent with Arenales, worn out by the endemic fevers of the coast, were more like spectres than men, so that the first movements of the expedition were very slow. The Cordillera was crossed by the Oyon Pass on the 6th May. The heights were covered with snow and the cold was intense. Aldao with the remnants of his division led the van. Pasco was occupied on the nth, and Carratala retired precipitately. Tarma and Jauja were taken on the 20th and 23rd, and Carratala continuing to retreat, the valley of Huancayo lay open to the Patriots on the 25th.
Arenales now prepared for a vigorous attack upon Carratala, when advice reached him of the signing of the armistice of Punchauca, which put a stop to operations for the present, retired to Jauja and employed himself in
