men, was almost surprised by Gamarra, of whose movements he knew nothing, and withdrew to the South. Gamarra was then joined by Lanza, the Guerilla chieftain, with 600 men, and learned that Urdininea, with the Argentine division, was advancing from Salta; but he lost the opportunity of destroying Olañeta, which was part of the plan of Santa Cruz, by remaining inactive at Oruro.
Santa Cruz, hearing that La Serna was concentrating his scattered divisions at Puno, then turned back to cover the line of the Desaguadero, and stationed himself on the left bank at the bridge of the Inca. Valdés advanced against him with 2,000 men, but finding the bridge was defended by artillery, he withdrew to the town of Zepita. Santa Cruz crossed the bridge and went after him, and overtook him in a strong position between the mountains and the lake of Titicaca. By a feigned retreat he drew Valdés into the plain, where two Peruvian squadrons cut the Royalist horse to pieces, but the attack upon the infantry was less successful, and night put a stop to the action. Both sides claimed the victory, but Valdés retreated, and soon after Santa Cruz returned to his position on the Desaguadero. This was the first and last battle of the expedition.
La Serna joined Valdés at Zepita, and crossed the Desaguadero with 4,500 men. Santa Cruz retreated before him, and on the 8th September joined Gamarra to the south of Oruro. He then manoeuvred to prevent a junction between La Serna and Olañeta, who was returning from Potosí with 2,500 men, but La Serna by a flank march over the heights succeeded in effecting the junction on the 14th September. Santa Cruz thought himself lost, and without attempting to bring on an action in which the chances would have been in his favour, retreated precipitately. The retreat soon became a flight, arms and baggage were thrown away, and he recrossed the Desaguadero utterly routed, without fighting and without even seeing an enemy. He left a company of infantry with two guns to defend the bridge, who capitulated to the Royalist vanguard at the
