Franklin was a northern province in Detina. It seceded with "King" Geoffrey during the Detinan Civil War. The Northern Army of Franklin was created to defend Franklin from the Southrons, but due to the inept commands of Count Thraxton the Braggart and General Bell the actual province was lost. The army was forced away from it province into Peachtree Province.
Franklin is analogous to the State of Tennessee. In reality, the State of Franklin (named for Benjamin Franklin in hopes of attracting his endorsement) was a short lived autonomous territory that existed from 1784-1788. It never received recognition from the United States government, and in time, the territory became part of eastern Tennessee.