Generalissimo denoted a military and political position held by a person serving as both the supreme military commander and the top civilian leader of a country. This title saw usage in several nations beyond the Tarleev area of the Unknown Regions. Circa 18 BBY, Admiral Ar'alani of the Chiss Expansionary Defense Fleet was involved in a skirmish above the planet Sunrise in the Unknown Regions against the Grysk Shatter-class WarMaster HopeBreaker. The commander of the Grysk ship referenced the title of generalirius. Ar'alani surmised that this title might be connected to the title of generalissimo, and she explained the meaning of the latter title to her subordinate, Senior Captain Xodlak'in'daro, whose core name was "Lakinda."
The generalissimo rank appeared in Thrawn Ascendancy: Greater Good, a 2021 novel and the second book of Timothy Zahn's Ascendancy Trilogy. In our world, a generalissimo signified the commander of a military force.