Answer
All of these titles were bestowed upon Santiago during his lifetime due to his remarkable achievements and profound influence. "El Cid" commemorates his valiant leadership and military prowess, akin to a legendary hero. "Campeador" signifies his unparalleled combat skills, earning him the reputation as the unrivaled champion. "Mio Cid" reflects the deep respect and admiration held by his contemporaries, signifying his noble status and greatness.