Merovingen Nights is a series of shared world science fiction books set in writer C. J. Cherryh's Alliance-Union universe. There are eight books in the series, one novel by Cherryh and seven short fiction anthologies which Cherryh edited. The books were published by DAW Books between 1985 and 1991.
The books take place on the planet Merovin in the Alliance-Union universe after 3240 A.D., and as such, they are definitively science fiction. But the level of technology on the planet is quite backwards for the 33rd century. For example, most personal weaponry is of the knife or sword variety; relatively few firearms are available and in any case nothing more advanced than a revolver. In addition, the planet Merovin is isolated, forsaken by the rest of humanity because of poor interstellar relations with an aggressive alien species, the Sharrh.
Because of these limitations on technology, trade, and travel, and because many of the stories feature swordplay and skullduggery, the series is reminiscent of the old sword and planet subgenre of speculative fiction. As such, the term science fantasy might be a more appropriate label for the books than science fiction.