Galahad is named first in the Vulgate Cycle though foreshadowed in the Perlesvaus. Though valorous and attractive, his overriding attribute is his chastity - absolutely essential for attainment of the Grail and why Lancelot, though noble in so many ways, can never succeed in the Quest. But he succeeds, in a way, through his son. Galahad has many adventures on the Quest, finally attaining his vision in Sarras and dying.
In medieval eyes, Galahad was seen as Christ-like. His name is derived from Gilead or "Galaad" in the Vulgate Bible (Gen. 31:48) and his character in part is an attempt to meld Christian and chivalric beliefs.