Veloso de Oliveira puts it at eight hundred thousand; and later statisticians range between one million five hundred thousand and seven to eight hundred thousand. The numbers given of Indians by the Spanish conquerors are almost always grossly overstated, from the wish they not unnaturally had to magnify the importance of their conquests and to enhance their exploits in the eyes of those for whom they wrote. Struck by the tractable character of the Guaranís, Mendoza began to build a fort on August 15, 1537 (which is the day of the Assumption), and the name he gave to his fort was Asuncion, which afterwards became the capital of Paraguay. Espinosa returned to Corpus Christi, and afterwards to Buenos Ayres, where a small force had still remained. This force, tired of the ceaseless battles with the Querandis, or Pampa Indians, embarked for Asuncion. Irala, after waiting for many months at Fort Olimpo, returned to Asuncion, where he found Ruiz de Galan acting as Governor. A dispute at once arose between them, and Irala, after having been imprisoned, was allowed to return to Fort Olimpo. Here he found the Payaguá Indians in rebellion, and in the battle which ensued he is reported to have slain seven of them with his own hand.[33] He still maintained a fitful search for Juan de Ayolas, but without success. Galan returned to Buenos Ayres, and, stopping at Corpus Christi, took occasion to fall upon the friendly and unsuspecting Timbú Indians and massacre a quantity of them. Why he did so is quite uncertain, for the Timbues had been in the habit of supplying the fort of Corpus Christi with provisions; it may be that the quality of the provisions was inferior, but neither Ruiz Diaz nor Schmidel informs us on the point. Galan, after his ‘victory’, re-embarked for Buenos Ayres, leaving Antonio de Mendoza in command with a hundred men. One day, when about the half of the force was hunting, the Indians fell upon it and cut it off to the last man; but for the opportune arrival of two vessels the fort would have been destroyed. However, many Spaniards were slain, and Antonio de Mendoza amongst them. After this battle, in which Santiago[34] is said to have appeared on the top of the principal tower of the fort dressed in white with a drawn sword in his hand, Galan and Espinosa returned to Asuncion, taking with them the remainder of the inhabitants of Buenos Ayres. At Asuncion they found that Irala had again returned without having discovered traces of Ayolas. Irala was elected Governor under a clause in the royal letters patent which provided for the case of Ayolas not returning. His first act was to order the complete evacuation of Buenos Ayres. An Italian vessel, which was going to Peru with colonists, having been driven into the river Plate, united with the remains of the colonists at Buenos Ayres and proceeded to Asuncion.