Thieves' World is a shared world fantasy series created by Robert Lynn Asprin in 1978. The original series comprised twelve anthologies, including stories by such science fiction authors as Poul Anderson, John Brunner, Andrew J. Offutt, C. J. Cherryh, Janet Morris, and Chris Morris. The Morrises introduced the Sacred Band of Stepsons in Thieves' World and spun off a series of novels about them and their ancient cavalry commander, Tempus. The first three novels in The Sacred Band of Stepsons saga were authorized Thieves World novels. Marion Zimmer Bradley was an early contributor but spun off her main character in the novel Lythande (1986) and did not return for later volumes. The series went on hiatus after the twelfth anthology. In addition to the official anthologies, several authors published novels set in the milieu of Thieves World.