Gonzalo Mariño arrived in Castile, reaching Córdoba, where the King of Castile was assembling as many forces as he could to effect his invasion. There he informed him that the town of Guimarães had been taken, and that Aires Gomes was being besieged and had been attacked with siege engines, towers and other appurtenant devices. The outcome was that he had entered into a truce for a number of days, thus enabling him to inform His Grace and Queen Beatriz, his wife, in whose names he held the town. He besought him to go to his aid or to send others to do so, or otherwise to release him from the pledge which he had assumed on behalf of the town, for he could no longer defend himself.

Having listened to these and other observations, the king stated that he already knew for sure that the Master of Avis, who called himself King of Portugal, had entered the town of Guimarães, and that Aires Gomes and those with him were in great difficulties as a result of the attacks which had been launched against them. Moreover, he considered that Aires Gomes and those who happened to be with him in the siege had rendered distinguished service both to him and to his wife the queen by dint of the tribulations which they had suffered there on their behalf. However, for the sake of such a town as Guimarães and its castle, even if it were of much greater importance, it was not his wish that a knight such as Aires Gomes, nor such noblemen as were with him, should be sacrificed.

Furthermore, the king said that Gonzalo Mariño could clearly see that he was amassing as many forces from his kingdom as he could, in order to invade Portugal to help Aires Gomes and the other noblemen who held towns and castles on behalf of himself and his wife Queen Beatriz. Besides that, he had already sent his fleet of naos and galleys to attack Lisbon and seize its port so as to prevent it from receiving any help either in provisions or in manpower.