Here are some of her most notable works:
The Wolves of Willoughby Chase series:
* The Wolves of Willoughby Chase (1962)
* The Blackthorn Tree (1963)
* The Cuckoo Tree (1965)
* The Whispering Mountain (1966)
* The Whispering Knights (1967)
* The Midnight Horse (1969)
* The Shadow Guests (1970)
* The Stolen Lake (1971)
* The Mysterious Mansion (1973)
Other fantasy novels:
* The Kingdom of Needlepoint (1974)
* The Dragon and the Unicorn (1975)
* The Spiderwick Chronicles (with Tony DiTerlizzi and Holly Black)
Historical fiction:
* The Adventures of the Black Girl in Her Search for God (1966)
* The Great and Terrible King (1972)
* The Young Visitors (1967)
* The Clockwork Dragon (1994)
Other works:
* The Middle Age of Mrs. Eliot (1967)
* The Whispering Wind (1973)
* The Gift of the Shadow (1977)
* The Winter Nightingale (1978)
* The Moonflower Garden (1981)
* The King's Knot (1985)
* The Devil's Engine (1988)
* The Night Ride (1990)
* The Accidental Sorcerer (1997)
She also wrote numerous short stories, poems, and essays.
Key themes in her work:
* The importance of courage and resilience in the face of adversity.
* The power of imagination and storytelling.
* The beauty and mystery of nature.
* The complexities of human relationships.
Joan Aiken's works are enjoyed by readers of all ages and continue to be popular today.