Each king drew up the forces he had with him, forming battle lines in accordance with the practice in Spain. Let us begin at once by describing the formation adopted by the King of Portugal, who was the first to do so and was ready waiting in the field. On level terrain, covered by green gorse, athwart the road along which the Castilians were bound to pass, he drew up the meagre force at his disposal in two small formations because there were not enough troops for any more.

In the first formation or vanguard was the constable, with his flag unfurled and with two squires next to him to guard both himself and the banner. In this formation there were just 600 lances. On the right wing, which began at the tip of this formation, were Mem Rodrigues, Rui Mendes de Vasconcelos and a cheerful company of other gallant noblemen who, on a point of honour and in defence of the realm, were intent on defending the position where they were drawn up. This flank was known as the ‘lovers’ wing’ and numbered some 200 lances all together. They displayed a huge green flag, designed by mutual agreement. On the opposite flank, on the left wing, there mingled with Antão Vasques and other Portuguese a number of foreigners, like Sir Guilhem de Montferrand, Martin-Paul and Basquin de Sola, as well as others, such as English archers and men-at-arms; all together they numbered another 200. As a result, to be fully drawn up, these wings lacked a further 200 men-at-arms, because in normal formations there should be as many on the wings as in the van. Those on the left wing bore a towering flag dedicated to Saint George, as well as other pennants. Accordingly, both the vanguard and the wings amply displayed a medley of banners and pennants to suit a variety of preferences, for at the time there was no king of arms or other herald to prohibit such displays. In addition, there were trumpets in certain spots, wherever required.

Behind the men-at-arms in both wings were stationed crossbowmen and foot soldiers, drawn up in such a way as to enable them to assist the men-at-arms and hinder their enemies.