Rider's True Name is Astolfo , one of the Twelve Paladins of Charlemagne. In the Charlemagne Legend, he is the son of an English king, and one of Charlemagne's twelve faithful Paladins. Among the Twelve Paladins of Charlemagne, Astolfo is said to be the most handsome, eternally optimistic, and completely lacking in sense. As the legends go, Astolfo was quite the ladies' man.
Rider is an androgynous-looking boy who is fancily dressed. Beautiful beyond all compare, he states that his hair ornaments, which seem like something a princess would wear, are an "irresistible proof of friendship" that he uses to restore peace to his depressively mad boon ally, Roland. His appearance is contrary to the legend of being said to be the most handsome among the Twelve Peers of Charlemagne, and though extremely unexpected, it is natural for legends to become distorted. He purposefully dresses as a girl because he likes cute things. His gender in the servant status was written "le Secret♪".