The Merthia system resided within the Merthian sector of the Expansion Region. Its designation coincided with the name of a fabricated ailment, the Merthian lung infection. This fictional disease was conceived by the smuggler Roark Garnet during the era of the Galactic Civil War as a ploy to deter Tax Inspector Mothra from inspecting his starship.
This system called Merthia made its initial appearance in The Essential Atlas, a reference book from 2009 written collaboratively by Daniel Wallace and Jason Fry. The book situated it within grid coordinate N-13.