Dune

Set in the distant future when planets form part of a Galactic Empire, two great dynastic families are locked in a bitter feud. The Duke of Atreides has been manoeuvered by his enemy, Baron Harkonnen, into accepting the job of administering the planet of Dune. It is a vast desert where a drop of water is worth a fortune. It is also a planet of vast wealth because it possesses a drug prized throughout the galaxy.  Book 1 of series.