The Mhalanduin system existed within the Oktos sector, situated in the Slice region of the Mid Rim. Its designation was the same as the Mhalanduin Reformation, a historical episode that transpired before 0 BBY.
This system, Mhalanduin, first appeared in the StarWars.com Online Companion that accompanied The Essential Atlas, a 2009 reference book. The companion placed it within grid R-12.