San Martin made small use of his victory. He at once despatched Freyre in pursuit with a party of cavalry, but not until the guerillas began to commit depredations did he send Zapiola with 250 grenadiers to maintain order in the South. Osorio made use of this respite to strengthen himself in Concepcion and Talcahuano, and, by calling in outlying detachments, succeeded in collecting 1,200 men by the middle of May.
Pezuela, who fully appreciated the magnitude of the disaster, wrote to the Viceroy of New Granada and Venezuela for reinforcements. Sámano sent him the Numancia battalion, 1,200 strong, weakening himself at the time that he was threatened by BolÍvar; but Morillo could send him none from Venezuela, and he confined his efforts to making preparations against invasion, leaving Osorio unaided to sustain himself in Chile as he could.
On the 21st May Osorio sent two detachments across the Nuble, one of which surprised the town of Parrol. Zapiola sent off Captain Cajaravilla with 200 horse to retake the town, which task he gallantly accomplished, capturing 70 prisoners; while Lieutenant Rodriguez of the grenadiers cut the other detachment to pieces at Quirihue. This put a stop to the efforts of the Royalists for that time, and Zapiola, being reinforced, determined to attack Chillán, where Colonel Lantaño was in command with a garrison of 500 men. The expedition was confided to Cajaravilla, who attempted to carry the place by assault, but was beaten off and compelled to retire.
Osorio, fearing that he would be attacked in the spring by the whole united army, resolved to evacuate Talcahuano, and to return to Peru. Accordingly, on the 5th September, he left Colonel Sanchez in command of the Chilian Royalists, and, after dismantling the fortifications, sailed for Callao on the 8th with thirty-five heavy guns, a great quantity of war material, and 700 Spanish troops—all that remained of the strong reinforcement he had brought with him.
