J. R. R. Tolkien published The Hobbit in 1937, and the first Lord of the Rings Book (The Lord of the Rings: The Fellowship of the Ring) in 1954.
He wrote/published The Hobbit before the Lord of the Rings series, which makes sense, as the Hobbit is a prequel to the Lord of the Rings.
However, Peter Jackson released the first Lord of the Rings movie (The Lord of the Rings: The Fellowship of the Ring) in 2001, and the first Hobbit movie (The Hobbit: An Unexpected Journey) in 2012.
Why did Peter Jackson release the movies in reverse order to the books?