English allies arrived at Easter of 1385, consisting of a company of about 100 English longbowmen, veterans from the Hundred Years' War, sent to honor the Anglo-Portuguese Treaty of 1373 (still the oldest active international treaty in the world). The Portuguese set out to intercept the invading army near the town of Leiria. Nuno Álvares Pereira took on the task of choosing the ground for the battle. Russell notes that the two Portuguese leaders Álvares and Antão Vasques had already shown themselves masters of the new developments in methods of warfare, i.e. the use of archers and dismounted men-at-arms. The chosen location was São Jorge near Aljubarrota, especially suitable for the chosen military tactic, being a small flattened hill surrounded by creeks, with the very small settlement of Chão da Feira (Fair's Ground) at its widest point, still present today.