يوسف بن تاشفين
The Battle of Sagrajas (23 October 1086), also called Zalaca or Zallaqa (), was a battle between the Almoravid army led by their King Yusuf ibn Tashfin and an army led by the Castilian King Alfonso VI. The battleground was later called "az-Zallaqah" (in English "slippery ground") because of the poor footing caused by the tremendous amount of blood shed that day, which gave rise to its name in Arabic.