The subsequent birth of two sons to Alfonso VII, the future kings Sancho III and Ferdinand II, and the geographic distance between Afonso's Portuguese power base and the Crown's, probably convinced Afonso to rebel in contravention of the Treaty of Tui (1137) and invade Galicia.

Upon hearing this, Alfonso VII rushed troops from León into Galicia, destroying fortifications that could be used by Afonso as they went, and camping in the Serra do Soajo north of the river Lima, of which the Vez is a tributary.

The King of Portugal likewise mobilized his army and marched out to fight the few men who had foolishly been separated from the Emperor's main force.

They joined in battle, and Ramiro was defeated and taken prisoner.The Emperor stationed his camp facing the castle at Penha da Rainha which is located in Portela de Vez.

The Portuguese King pitched his tents facing the Emperor's camp on a higher and rougher terrain with a valley lying between the two.

the Emperor Don Alfonso, son of Count Raymond and Queen Doña Urraca, daughter of the Emperor Don Alfonso, having assembled his entire army of Castile and Galicia, wished to enter the kingdom of Portugal and arrived at a place called Valdevez.

But the king of Portugal, Afonso, joined with his army and coming in the manner he wished, drew up his tents, some in that place and others elsewhere.

Certain people came from the Emperor for a game [ex parte Imperatoris ad ludendum], which is popularly called a “bufurdio” [Bufurdium], and immediately the men of the king of Portugal came down and fought them.

[7] In Arcos de Valdevez a monument by sculpture José Rodrigues commemorates the battle as a joust.

Per idem tempus Imperator D. Alfonsus filius Comitis Raymundi, & Reginae Donnae Orracae filiae Imperatoris magni D. Alfonsi, coadunato omni exercitu de Castella, & de Gallecia, voluit intrare Regnum Portugalliae, & venerunt usque ad locum qui dicitur Valdevez; sed Rex de Portugal D. Alfonsus occurrit ei cum exercitu suo, & obsedit iter, per quod ille venire volebat, fixitque tentoria sua, isti ex hac parte, & illi ex altera parte, cumque veniret aliquis ex parte Imperatoris ad ludendum, quod populares dicunt Bufurdium, statim egrediebantur ex parte Regis Portugallis occurrentes eis, & ludentes cum eis, qui in exercitu comprehenderunt Fernandum Furtado fratrem Imperatoris, & Consulem Pontium de Cabreira, Veremundum Petri, & Varella filium de Fernando Joannis germanum de Pelagio Curvo, & Rodericum Fernandi patrem de Fernando Roderici, & Martinum Kabra consobrinum Consulis D. Pontii, & alios multos, qui cum eis venerant.