Geralt is the son of the sorceress Visenna and, presumably, the warrior Korin. Shortly after his birth, Geralt was taken by his mother to the School of the Wolf at the stronghold of Kaer Morhen. There, Geralt was trained and made to be a witcher. He survived the many blistering mutations required to grant witchers their abilities and passed the Trial of the Grasses. Geralt's intensive training, and the mutagenic experimentation carried out upon him, have granted him considerably greater strength, speed, endurance, resilience, healing, senses, complete immunity to diseases and conventional poisons, and an extreme resistance to pain. Due to his brilliant success in training, Geralt was selected for additional mutation experiments. He is the only witcher to have survived these experiments, his stark white hair being a side effect of these additional mutations. After finishing his witcher training, Geralt embarked into the world on a horse named Roach, a name he would bestow upon every one of his later horses. Thus, he became a monster slayer for hire.Most of the time, he can be apathetic, cynical, and threatening. Despite his outwardly cold nature, Dandelion notes that behind his exterior hides a fiercely loyal friend, and a man of good humour and as someone not indifferent to suffering. Geralt is shown in the books and games to have many good friends all over the Northern Realms, such as Caldemeyn of Blaviken, Zoltan Chivay, and of course Dandelion. He is also very protective of and loyal to his friends and companions, and is willing to go to great lengths for those who matter to him. He can be kind-hearted and caring to the people he loves.