The Seeing Stone - Kevin Crossley-Holland

The year is 1199, the place the Welsh Marches. Young Arthur de Caldicot is given a shining stone in which his legendary namesake is revealed.
In 100 short chapters that brilliantly evoke life in a medieval manor, stories of the boy King Arthur begin to echo and anticipate the secrets and mysteries that emerge in his own life.

as bright and as vivid as the pictures in a Book of Hours. Deep scholarship, high imagination, and great gifts of storytelling have gone into this; I was spellbound. Philip Pullman, The Guardian

instantly evokes T H Whites The Once and Future King in blending the pastoral idyll of a medieval manor with the myths of King Arthur. There the similarity ends
this is truly a crossover book, settling in the interesting space between childrens and adult fiction. The Times