The hollow hills

"Arthur, the future King, is born and sent off into hiding while Merlin travels, doubting his own powers. Finally becoming reassured of his mission, he is reunited with Arthur when the boy is almost a man and sees him established as King."@en
"Merlin's story continues with the birth of King Arthur."@en
"The story of how Merlin rears Arthur, the future King, in remote secrecy, told in the voice of Merlin himself."@en
"In this sequel to The Crystal Cave, Merlin conceals and grooms the child Arthur until the time of his coronation."@en
"Keeping watch over the young Arthur Pendragon as he grows, the prince and prophet Merlin Ambrosius is haunted by a vision of a magical sword -- the fabled sword Caliburn, hidden for centuries. Sheathed in fire and stone, water and ice, the sword of the Emperor Maximus is destined to reveal the true High King. When Uther Pendragon is killed in battle, the time of destiny is at hand, and Arthur must claim the sword from a perilous chapel to claim his destiny and become the true High King of Britain."
"Arthur, the bastard son of King Uther, is rejected by him. Merlin the magician supervises Arthur's exile and guides him to the throne and a dazzling reign."