The Great Mouse Detective is a 1986 American animated mystery-comedy film produced by Walt Disney Feature Animation, originally released to movie theaters on July 2, 1986 by Walt Disney Pictures. The 26th feature in the Walt Disney Animated Classics, the film was directed by Burny Mattinson, David Michener, and the team of John Musker and Ron Clements, who later directed Disney's hit films The Little Mermaid and Aladdin. The film was also known as The Adventures of the Great Mouse Detective for its 1992 theatrical re-release and Basil the Great Mouse Detective in some countries. The main characters are all mice and rats living in Victorian London.
Based on the children's book series Basil of Baker Street by Eve Titus, it draws heavily on the tradition of Sherlock Holmes with a heroic mouse who consciously emulates the detective; Titus named the main character after actor Basil Rathbone, who is best remembered for playing Holmes in film (and whose voice, sampled from a 1966 reading of "The Adventure of the Red-Headed League" was the voice of Holmes in this film, 19 years after his death). Sherlock Holmes also mentions "Basil" as one of his aliases in the Arthur Conan Doyle story "The Adventure of Black Peter".
After the failure of Disney's previous animated feature film The Black Cauldron, this simpler film proved to be a success upon its initial release in 1986. As such, the new senior management of the company were convinced that their animation department was still a viable enterprise and this set the stage for the Disney Renaissance.
In London, circa 1897, a young mouse named Olivia Flaversham is celebrating her birthday with her toymaker father, Hiram. Suddenly, Fidget, a bat with a peg leg, barges in, and after a brief struggle, disappears with Hiram. Fidget takes Hiram to Professor Ratigan who commands him to create a clockwork robot which mimics the Queen of the Mice so Ratigan can rule England. Hiram initially refuses to participate in the scheme, but agrees when Ratigan threatens Olivia.