Dune is set far in humanity's future. Within those years, Earth has been destroyed, a Jihad has taken place to free humanity from the 'thinking machines' that threatened to overwhelm the human race, and mankind has scattered throughout space. This Universe is a feudal empire ruled by the Padishah Emperor Shaddam Corrino IV of House Corrino. The novel focuses on a rivalry between two feudal houses - House Atreides and House Harkonnen.
Dune is the first of six novels written by Frank Herbert set in this universe:
Dune Messiah (1969)
Children of Dune (1976)
God Emperor of Dune (1981)
Heretics of Dune (1984)
Chapterhouse Dune (1985)
Frank Herbert died in 1986. His son Brian Herbert and Kevin J. Anderson have written several more novels set in the Dune universe..