Grendreef

Grendreef was an admiral in the naval branch of the Galactic Empire's Imperial Military. Alliance to Restore the Republic intelligence officer Cassian Andor served undercover for a time as Grendreef's assistant using the operational alias "Joreth Sward", sometime prior to Andor's death in the year 0 BBY.

Behind the scenes
Grendreef first appeared as one of the villains in The Isis Coordinates, a Star Wars Legends adventure written by Christopher Kubasik and released in June, 1990 for West End Games' Star Wars: The Roleplaying Game. Grendreef was then mentioned in canon for the first time in the reference book Star Wars: Rogue One: The Ultimate Visual Guide, which was written by Pablo Hidalgo and released on December 16, 2016.