Geralt of Rivia was a legendary witcher of the School of the Wolf active throughout the 13th century. He loved the sorceress Yennefer , considered the love of his life despite their tumultuous relationship, and became Ciri 's adoptive father.
During the Trial of the Grasses , Geralt exhibited unusual tolerance for the mutagens that grant witchers their abilities. Accordingly, Geralt was subjected to further experimental mutagens which rendered his hair white and may have given him greater speed, strength, and stamina than his fellow witchers. Despite his title, Geralt did not hail from the city of Rivia. After being left with the witchers by his mother, Visenna , he grew up in their keep of Kaer Morhen in the realm of Kaedwen.
In the interest of appearing more trustworthy to potential clients, young witchers were encouraged to make up surnames for themselves by master Vesemir. As his first choice, Geralt chose "Geralt Roger Eric du Haute-Bellegarde", but this choice was dismissed by Vesemir as silly and pretentious, so "Geralt" was all that remained of his chosen name.
Later, Queen Meve of Lyria knighted him for his valor in the Battle for the Bridge on the Yaruga conferring on him the formal title "of Rivia", which amused him. Geralt was born as the son of the sorceress Visenna and presumably, the warrior Korin. Shortly after his birth, his mother left him with the School of the Wolf at the stronghold of Kaer Morhen.
There, Geralt was made and trained to become a Witcher. As a child, he was subjected to the Trial of The Grasses. He managed to survive the many blistering mutations required to grant Witchers their abilities. After displaying unusual tolerance, Geralt was selected for further experimental mutations which granted him considerably greater strength, speed, endurance, resilience, healing, senses, complete immunity to diseases and conventional poisons, and extreme resistance to pain.
