‘My liege lord, the King of Castile, my master, sends me to say that you sent a messenger to him claiming that you have a greater right to the kingdom of Castile than he has, and that, if he were to deny this, you would engage with his forces in a pitched battle. To this my liege lord the king now replies that he has a more rightful claim to the realms of Castile than you have, and that, if you reject this, then he will fight you in single combat, or ten against ten, or 100 against 100, whichever you prefer, because in the service of God and to avoid the spilling of Christian blood, he is anxious not to enter a pitched battle.’

‘My lord, on behalf of my liege lord the King of Castile, and in defence of his rightful claim, let me say this: as regards the kingdoms of Castile and León to which you are a claimant through your wife, alleging that she has a right to them because she is the daughter of King Pedro, with due respect, I must answer that claim, by saying that your wife Princess Constanza has no right to them whatsoever. The reason is this: King Alfonso, who was elected emperor, was the son of King Fernando, who won Seville from the Moors.