Astolfo is a former Servant turned into a human by his master's wish to the Holy Grail. He is the former Rider of Black from the Great Holy Grail War thirteen years before. Kept manifested by the Greater Grail, he is recruited by the Mages' Association and willingly makes a Master-Servant contract with Leo Solaris, if not a temporary one.
Rider's True Name is Astolfo (アストルフォ, Asutorufo?), one of the Twelve Paladins of Charlemagne (シャルルマーニュ十二勇士, Sharurumānyu Jūni Yūshi?). 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. As a cousin of Roland, Astolfo is included among those twelve-- that being said, Astolfo was famed as "weak" in legends.
Astolfo has created many legends as he was an adventurer who flew to all over the world and even reached the Moon in the end. Through his journeys, he had won numerous Mystic Codes such as his flute, his grimoire, and his shining golden lance. Astolfo brought rise to various legends on the back of mounts like a griffin and the famous Rabicano, but particularly famous among them is something inconceivable for this world—the Hippogriff.
Although many are the glorious tales of Astolfo, it is said that he has made just as many mistakes. He was continually defeated in riding tournaments, fell victim to many thaumaturgical traps and even lost—in a matter of hours—the reason that he had picked up at the moon. However, Astolfo never faltered; he did not seem to consider failure or defeat as blunders in the first place.
