While Nuno Álvares was in Évora, he received a message informing him that a great and most notable knight called Juan Rodríguez de Castañeda, who captained 300 lances, together with García Fernández [de Villagarcía], the Grand Commander of the Order of Santiago, and other knights and most valiant men, had arrived at Badajoz, saying that he wished to come and seek him out. Some say that he was sent by the King of Castile. As soon as he heard this, Nuno Álvares set out immediately for Elvas before Juan Rodríguez could leave Badajoz, in order to spare him the effort.

When Juan Rodríguez learned that Nuno Álvares was in Elvas, 3 leagues away, he sent one of his trumpeters to tell him that he was well aware that his liege lord the King of Castile was King of Portugal by right, and that, if Nuno Álvares were pleased to serve him and be his vassal, he would arrange with the king to increase his estate and grant him many favours. Also, that if Nuno Álvares did not want to do so, he would come to him; Nuno Álvares should wait for him there, because he would be with him the following day to engage in a battle, should he wish to enter it. He ought to see full well that it was wrong to wage war on the king in his own domain.

Nuno Álvares received the trumpeter courteously and gave orders for him to be comfortably lodged. Then he replied to the effect that he should tell Juan Rodríguez that he himself was fully aware that, in the treaty the King of Castile had made with King Fernando, when he had married the latter's daughter, there were certain clauses which he had not respected, and he had entered the kingdom in contravention of the oath he had sworn. Also, that Juan Rodríguez should send word to the King of Castile to raise the siege on Lisbon and return to his country, maintaining the terms of the treaty as they had been set out. Thus they could all be in agreement, otherwise not.