The episode took place in the spring of 1141, in the Valley of the Time, in Arcos de Valdevez, when D. Afonso Henriques, after the victory in the battle of Ourique (1139), broke the peace of Tui (1137) signed with his cousin the Emperor Alfonso VII of Leon and Castile, and invaded Galicia, conquering some castles under the protectorate of the monarch of Leon. In response, the imperial forces, in a much larger number, entered Portucalenses lands, sweeping the castles as they passed, descending the Soajo mountains towards Valdevez.
After a few hours of brawls and taunts, to avoid pitched battle and spare men and resources to fight the Arab breakthrough, the best riders on both sides were selected to fight each other in a tournament or fair, as was the use in the Middle Ages . The fortunes of the guns fell to the Portuguese side, and the Leonese horsemen were detained, according to the code of the medieval cavalry.
This was the decisive episode and the last stage for the birth of Portugal, being the antecedent of the celebration of the Treaty of Zamora in 1143.