Martin of Leon was a 12th-century priest and Augustinian canon regular born in León. Following his mother's death, he joined the canonry of San Marcelo with his father, Juan. After studying in Paris under Peter Lombard and traveling to Rome and Constantinople, he eventually joined the collegiate church of San Isidoro. His life was marked by extensive travel, including participating in the Third Crusade and serving the Hospitallers in the Holy Land for two years. He is remembered as a devoted figure known for his piety and charitable works.