Battle of Sagrajas

The Battle of Sagrajas (23 October 1086), also called Zalaca or Zallaqa, Arabic: معركة الزلاقة‎), was a battle between the Almoravid army led by the Almoravid king Yusuf ibn Tashfin and a Christian army led by the Castilian King Alfonso VI. The battleground was later called az-Zallaqah (in English "slippery ground") because the warriors were slipping all over the ground due to the tremendous amount of blood shed that day, and this gives rise to its name in Arabic.

• http://en.wikipedia.org/wiki/Battle of Sagrajas