Which author won the Newbery Medal for the 1976 book 'The Grey King'?

Susan Cooper won the Newbery Medal for The Grey King in 1976.

The Grey King was published in 1975 and is the fourth novel in Cooper's five-book fantasy sequence The Dark Is Rising. The story sends Will Stanton to Wales while he recovers from illness. There he meets Bran, a mysterious boy connected to King Arthur, and becomes involved in a quest to find a golden harp and awaken ancient sleepers who can oppose the Dark.

Cooper blends Welsh landscape and folklore with Arthurian legend, presenting a modern world in which ordinary places conceal mythic forces. The novel's Welsh setting is especially important: its mountains, legends, and language-related traditions give the fantasy a strong sense of place rather than making it a generic battle between good and evil.

A frequent source of confusion is the publication date. The novel appeared in 1975, but the Newbery Medal was awarded in 1976. Cooper had already received a 1974 Newbery Honor for The Dark Is Rising, the sequence's second book, before winning the medal for The Grey King.