The Second Battle of Olmedo was fought on 20 August 1467 near Olmedo in Castile (now in the province of Valladolid, Spain) as part of the War of the Castilian Succession between Henry IV of Castile and his half-brother Alfonso, Prince of Asturias. Alfonso's troops advanced eastwards along the valley of the Duero towards central Castile, while the troops loyal to Henry moved north from Cuéllar towards Medina del Campo to try to cut them off: the two armies met near Olmedo. Henry's troops comprised: