alfonso xi left seville on 15 october 1340 with a relief army, joining the king of portugal the next day. they advanced to the line of the guadalete river and there awaited further castilian and portuguese contingents. at last on 26 october the combined army, now 20,000-strong, crossed into enemy territory. when informed of their advance, abu hasan ordered the siege raised and his army took position on a hill between tarifa and the sea. yusuf i placed his army on an adjacent hill. on the 29th the christian army reached the deer hill (hayar al-ayyal), from tarifa and barely 250 metres from the beach. between them and their adversaries was a 4500m long valley crossed by the streams of la jara and el salado. with supplies running low, alfonso xi decided to attack the next day.