A prominent division of the New Armes Kingdom's national army. The name of the division most likely comes from it's prominence on New Armes southern border, with the Falena Queendom, that is comprised of rocky terrain and mountains. In 449, the Armes Southern Mountain Corps agreed to an alliance with the Falenan House of Barows which would see the lands of Barows become a New Armes vassal state, however the plan was foiled by a joint Godwin-Loyalist offensive once the New Armes troops revealed themselves, much to the disgust of Acting Mountain Corps commander, Jidan Guisu.
In 450, at the height of the Falenan Civil War (449-450), New Armes allied themselves with the Godwin regime in their war against the Loyalist Army. The Armes Southern Mountain Corps, commanded by Maha Sparna and assisted by Jidan Guisu, took Sable and Lordlake, the Loyalist Army being hopelessly outnumbered in their battles. Known for being overly-roughly, the Armes Western Marine Corps were also dispatched, not to aid in the war effort but to carefully monitor the movements of the Southern Mountain Corps.
The Southern Mountain Corps was eventually repelled from Falena, resulting in the death of Jidan Guisu and the execution of Maha Sparna who was pinned by New Armes as a scapegoat for the disastrous military excursion.
The Armes Southern Mountain Corps effectiveness was heavily limited by corruption, causing equipment to be very much below par due to high-ranking officers diverting funds for their own personal gain. However, this has possibly changed following the death of Jidan Guisu and the execution of Maha Sparna.