context: The Battle of Al-Zallaqa or the Battle of the Plain of Plain (on Friday 12 Rajab 479 AH / 23 October 1086), [1] is considered the first major battle in the Iberian Peninsula in the Middle Ages [2] and one of the most significant major battles in Islamic history. In it the Emir of Muslims Yusuf Ibn Tashfin, the leader of the Almoravids, supported by the Andalusian army led by Al-Mu'tamid bin Abbad, the owner of Seville, was able to inflict a major defeat on the Christian Castilian army led by Alfonso VI of King Castile and Leon. The battle took place after the deterioration of the conditions of Andalusia, which led to the subordination of Alfonso VI to the authority of the sects and the payment of tribute to him, and this situation ended with the fall of Toledo in the hands of Alfonso and his army in 478 AH corresponding to 1085 AD, that is, one year before the Battle of Zallaqah. As a result, the people of Andalusia and their princes sent embassies and letters to Prince Yusuf bin Tashfin asking him for help and asking him for relief and support, and he responded to them and across the sea with the Almoravid army to support the Muslims of Andalusia, and unified the army of Andalusia with the army of Almoravids in a large army led by Ibn Tashfin. The army marched until the Plain of Al-Zallaqah arrived, and Alfonso VI marched to it with a large army that gathered from across Europe, and a great battle took place between the two armies, which ended with the victory of the Muslims with a great victory, and the defeat of the Christian Castile Army. [3]
question: Where was the rule of Castile king Alfonso?
answers.text: Castile and Leon