Battle of Alarcos
1195 CE.
Shown on the map at 38.953°, -4.000°.
Battle of Alarcos (July 18, 1195), was fought between the Almohads led by Abu Yusuf Ya'qub al-Mansur and King Alfonso VIII of Castile. It resulted in the defeat of the Castilian forces and their subsequent retreat to Toledo, whereas the Almohads reconquered Trujillo, Montánchez, and Talavera.
Text from the Wikipedia article Battle of Alarcos, licensed CC BY-SA 4.0.