Hualcopo retired to Riobamba, but there it was impossible to maintain himself, and he was forced to retreat to the fortress of Mocha in the nudo which divides Riobamba from the valley of Latacunga. Here he made a determined and successful stand, and all Tupac's efforts to force his way over the last line of natural fortifications which kept him out of the northern valleys were in vain. The Inca emperor was forced to content himself with assuring his possession of the provinces already conquered. In 1460 he returned to Cuzco, leaving the territory garrisoned. Three years later the heroic Hualcopo died, and was succeeded by his son, Cacha, the fifteenth and last Shiri. The young man signalised his accession to the throne by an aggressive campaign for the recovery of the lost provinces. He passed south into the valley of Riobamba, surprised the Inca garrisons, and put them to the sword, revindicating all the country as far south as the nudo of Azuay. Beyond that range he was unable to go, for all his efforts failed before the obstinate resistance of the inhabitants of Canar. Tupac began preparations to lead an overwhelming army against Cacha, but his own death interrupted him, and it was not until 1475 that his son, Huaina Capac, surnamed the "great," was able to take the road for the north, determined to put an end to the Shiri dynasty. He first consolidated his power among the tribes on the coast south of Guayaquil, whom his father had left half independent, and then extended his conquests along the northern shore among the barbarians of Manabi. On the island of Puna he put to the sword all the male inhabitants, and one tribe in Manabi, notorious for its abominable and unnatural practices, he extirpated. Returning south, he crossed the mountains in northern Peru, and descending their eastern slopes, waged a bloody war against the Pacamores, who inhabited the forests where the Upper Amazon debouches into the plain. Having thus secured his line of communications he devoted himself to the main object of the campaign--the conquest of Quito.