King Alfonso VI of León was a significant ruler in medieval Spain, reigning from 1065 to 1109. He is best known for uniting the kingdoms of León and Castile, which strengthened his power and influence in the region. His reign marked a period of cultural and military expansion, as he sought to reclaim territories from the Moors. Alfonso VI was also known for his support of the Christian Reconquista, a series of campaigns aimed at reclaiming the Iberian Peninsula from Muslim rule. His leadership helped to establish León as a major political center, and he is remembered for his contributions to the development of Spanish identity during the Middle Ages.