Fantasy comics have been around as long as comics. The classification "fantasy comics" broadly encompasses illustrated books set in an other-worldly universe or involving elements or actors outside our reality. Fantasy has been a mainstay of fiction for centuries, but burgeoned in the late 1930s and early 1940s, spurred by authors such as C.S. Lewis and J.R.R. Tolkien. They inspired comic book producers. Fantasy-themed books—driven by superhero comics gaining popularity through the 1960s—grew to dominate the field. In the 1990s, authors such as Neil Gaiman helped expand the genre with his critically acclaimed Sandman series.