Satisfied with the extent of the conquests he had made, or rather with the incursions he had been able to make in the Araucanian territory, Valdivia now retraced his steps towards the north; and in his progress during the year 1553, he built fortresses in each of the three Araucanian provinces of Paren Tucapel and Arauco. From the warlike inhabitants of these provinces especially, he apprehended any attempt that might prove fatal to his more southerly settlements of Imperial Villarica and Valdivia, and he left garrisons in these more northern fortresses to preserve the communication, and to be in readiness to afford succours to the others in the south. According to the poet Breilla, the Spaniards had to sustain many battles and encounters with the natives in the course of this expedition in Araucania, but the particulars of none of these are recorded. This is however very probable; as it is not easy to account for the continuance of Lincoyan in the command on any other principles. It may be concluded, however, that, owing to the caution, or cowardice rather of the Araucanian toqui, these actions were so ill conducted and so inconclusive, as to give very little interruption to Valdivia in his triumphant progress through these provinces, between the Biobio and Callacalla, or from Conception to Valdivia. On his return to St Jago, the seat of government, Valdivia received a considerable body of recruits to his army from Peru, together with 350 horses; on which he dispatched Francisco de Aguirre with two hundred men, to reduce the provinces of Tucuman and Cajo on the eastern side of the Andes; not considering how inadequate was even his whole undiminished military force to retain so large an extent of country as that he had now occupied, and a so numerous and warlike people under subjection. Indefatigable in the execution of his extensive plans of conquest, Valdivia returned into Araucania, where he founded in the province of Encol, a city to which he gave the name of La Frontera, being the seventh and last of his foundation. This name, from events which could not then have been in the consideration of Valdivia, has become strictly applicable to its present situation, as its ruins are actually situated on the southern confines of the Spanish settlements in Chili. Though long ago destroyed, it is still mentioned by geographers as an existing city under the name of Angol, by which native denomination it was long known to the Spaniards. It was situated in a fertile district, excellently adapted for the cultivation of vines, and for some time was in a rich and flourishing condition, principally owing to its wines, which were in great repute at Buenos Ayres, to which place they were transported by a road across the Andes and through the plains of La Plata.