While Villagran was using every possible exertion to maintain the Spanish power in the south of Chili, by combating the brave and victorious Araucanians, he found himself on the point of being compelled to turn his arms against his own countrymen.  It has been already mentioned that Valdivia, in the instructions he left with the magistrates of Conception before his fatal expedition into Araucania, had nominated Francisco Aguirre in the second place as his own successor in the government, and that Villagran, only third in nomination, had succeeded to the command in consequence of the absence of the other two who were prior to himself.  When Aguirre, who was then in Cujo, where he does not appear to have effected any thing of importance, was informed of the death of Valdivia, and his own destination to the government of Chili, he considered the assumption of the vacant command by Villagran as prejudicial to his own just rights, and immediately returned into Chili with sixty men who remained of his detachment, determined to acquire possession of the government by force or favour.  His pretensions and those of Villagran must infallibly have kindled a civil war among the Spaniards in Chili, to the ruin or vast detriment of the Spanish interest, had not the competitors agreed to submit the decision of their respective claims to the royal audience at Lima, which at that time, 1555, held the supreme legal jurisdiction over all the Spanish dominions in South America.  On this appeal, the court of audience thought proper to set aside the pretensions of both competitors, and issued an edict authorizing the corregidors of the different cities to command each in their respective districts, till farther orders.  Perceiving the extreme inconvenience that must have necessarily resulted to the interests of the colony, from this divided government, especially during so important a war, the principal inhabitants remonstrated against the impolicy of this decree.  The royal audience listened to the representations of the colonists, and appointed Villagran to resume the command, but only granted him the title of corregidor, and gave him orders to rebuild the city of Conception.  Although convinced of the inutility of this measure in the present conjuncture, Villagran, in obedience to the orders, proceeded immediately to that place with eighty-five families, whom he established there, and erected a strong fortification for their defence.

The native inhabitants of that part of the country which formed the territory of Conception, were indignant at being again subjected to the intolerable yoke of the Spaniards, and had recourse to the Araucanians for protection.  Caupolican, who seems at this time to have remained in almost entire inaction, either ignorant of the proceedings of the Spaniards, or from some other cause of which we are not informed, immediately sent Lautaro at the head of two thousand warriors to the assistance of the distressed natives on the north