A year later a similar effort was made by an army of five thousand Peruvians under the command of Santa Cruz, a Bolivian half-breed of noble Inca lineage who had been engaged in the Spanish service until 1821, and then, deserting, had risen to supreme power in the patriot army after the retirement of San Martin. Northern Bolivia had been denuded of troops by the Spanish generals in the course of their operations near Lima. No army disputed the pass, and Santa Cruz penetrated to La Paz without opposition. Valdez hastened from Peru, and the Spanish army in southern Bolivia moved toward the threatened region. Santa Cruz's position lay directly between them; his forces were superior to either of the Spanish armies and apparently it would not be difficult for him to whip them in detail. But he made the mistake of dividing his own forces, and Valdez came up with such unexpected speed that he failed to unite his two divisions before the Spaniards reached La Paz. He retreated to the south in order to join his other division, closely followed by the enemy, and scarcely had he effected the junction when Valdez skilfully outflanked him and united his forces to the army of southern Bolivia. By this manoeuvre the patriot army found itself hopelessly outnumbered and fled north in disorder. By the time it reached the coast it had been practically annihilated. One body of Spaniards resumed at its leisure a position threatening Lima, while the Bolivian division occupied itself with crushing the insurgents who had risen at Cochabamba and other points during Santa Cruz's stay upon the plateau. This disastrous campaign seemed to destroy all hope of Bolivian freedom for years to come. But Olaneta, the renegade Argentine who commanded the Spanish army in Bolivia, quarrelled with La Serna and the northern generals. They sent a force to fight him, and while the Spaniards were thus warring among themselves word was received that Bolivar had arrived on the Peruvian coast, accompanied by his great lieutenant, Sucre, and a large army of Colombian veterans. To meet this pressing danger the viceroy abandoned his efforts to reduce Olaneta to submission, recalled the troops he had sent into Bolivia, and sent north as large a force as he could muster. Bolivar climbed the coast range unopposed and met the Spanish army not far south of Cerro de Pasco. On the 24th of August, 1824, he won the cavalry action of Junin, and the Spaniards were compelled to retire to Cuzco. Bolivar went to Lima to consolidate his political position, leaving the command with Sucre. Four months later the viceroy suddenly broke out of Cuzco, outmanoeuvred Sucre, and marched toward Lima closely followed by the Colombian forces. The two armies finally met at Ayacucho, December 9, 1824, and though the royalist army fought on a field of its own choosing and had the advantage in numbers and artillery, it was annihilated.