After this cattle raid and seizure of booty was over, Pero Rodrigues discovered for certain that Vasco Porcalho, the grand commander, was receiving letters from Pero Rodrigues da Fonseca contrary to the Master's service. He arranged for this information to be passed on by one of his squires to Álvaro Coitado in Vila Viçosa. When the squire arrived with this message, Vasco Porcalho happened to be in the town square. Álvaro Gonçalves made ready to arrest him, and he began by talking to a number of townspeople. Having secured the postern gate, where he posted crossbowmen and foot soldiers, with orders not to let anybody in or out, he ordered ten squires to be posted at the castle gate and commanded all the town's gates to be barred. Then, in great haste, he summoned Pero Rodrigues from Alandroal, which is a league away. On reading his message, Pero Rodrigues rode off with ten squires and sixty foot soldiers and very quickly reached Vila Viçosa.

Álvaro Gonçalves had already taken control of a huge tower which stands over one of the gateways and gave the order for the gate to be opened for Pero Rodrigues. The moment they saw each other, they entered into a discussion that nobody heard. Then they set off at once, with their forces and all the townsfolk, to the palace of the Order [of Avis], where the commander was already to be found, with fifteen squires, thirty foot soldiers and ten crossbowmen; in addition, the street leading to the palace was well defended by barricades.

The huge throng immediately battered down the barricade, with everybody yelling out, ‘Death to the traitor and all his men! Death for selling us out to the King of Castile!’ Though everyone was calling for the palace to be set alight, they were made to quieten down, and a message was sent to the commander telling him to come out, so that they could talk to him, or they would go in, whichever he preferred.

When once Vasco Porcalho and his men had been given assurance of their own safety, he emerged from the palace to speak to Pero Rodrigues and Álvaro Gonçalves.