A little while after this – it could have been around three years later – the marriage was arranged between King João's daughter [Beatriz], the sister of the said Count of Barcelos, son-in-law to the constable, and Thomas, Earl of Arundel, an honourable lord of the House of England. The man who arranged this marriage was the honourable knight João Vasques de Almada, a citizen of Lisbon, who at that time was in England. The king sent this man and a doctor of laws called Martim do Sém to London where they arrived in the month of February. On the seventh day of that month they talked to the earl in person in his palace about the things pertaining to this marriage. After discussing many things necessary for such business, they came to an agreement, as follows:

If the earl's ambassadors, whom the earl intended to send to Portugal on this matter in order to see her, were content with the beauty, physical makeup and gracefulness of this Dona Beatriz, they were to receive her in his name. The king would give as her dowry 50,000 crowns, 25,000 paid in the first instance and the rest from the day on which she was received in England up to a year following. The king would send her at his expense, with all due honour, as befitted them both. If the earl died before she did, she would afterwards have a third of the sum he was given for the maintenance of her status during her lifetime. There were other conditions that are not worth recording.

The Portuguese ambassadors left and English ambassadors came to Portugal, namely Sir John Wiltshire, a knight of the earl's household, who was his principal proctor for this matter, Master John, a doctor in canon law, along with a worthy squire who came with them. All three arrived in Lisbon where the king then was and spoke to him about the matter for which they had been sent. All was agreed and the ambassadors were indeed content with the beauty and physical makeup of the king's daughter.