The Castilian vanguard arrived from the north around midday. Seeing the strongly defensive position occupied by the Portuguese, John of Castile decided to avoid combat on John of Portugal's terms. Slowly, due to the numbers of his army (about 31,000 men), the Castilian army started to contour the hill where the Portuguese were. John of Castile's scouts had noticed that the South side of the hill had a gentler slope and it was there that the Castilian king wanted to attack.