In 1086, on this day the forces of Alfonso VI King of León and Castile won a decisive victory fought in treacherous conditions over the Almoravid army at the Battle of az-Zallaqah ("slippery ground").
Castilian Victory at the Battle of the Slippery GroundAfter the Castilians had captured Toledo and invaded the taifa of Zaragoza, the emirs of the smaller taifa kingdoms of Islamic Iberia found that they could not resist against him without external assistance. Yusuf ibn Tashfin was invited by them to fight against Alfonso VI and he replied to the call of three Andalusian leaders (Al-Mu'tamid ibn Abbad and others) and crossed the straits to Algeciras and moved to Seville. From there, accompanied by the emirs of Seville, Granada and Taifa of Málaga marched to Badajoz. To do so, he was forced to abandon the siege of Zaragoza, recall his troops from Valencia and appeal to Sancho I of Aragon for help. Finally he set out to meet the enemy northeast of Badajoz. The two armies met each other on 23 October 1086.
Alfonso VI of Castile reached the battleground with some 2,500 men, including 1,500 cavalry, in which 750 were knights, but found himself outnumbered. The two leaders exchanged messages before the battle. Yusuf ibn Tashfin is reputed to have offered three choices to the Castilians: convert to Islam, to pay tribute (jizyah), or battle. Despite some signs of panic in the Castilllian army  Alfonso (pictured) managed to control his troops and the result was a decisive victory for the Reconquistadors.