Dwarven, Common - Arenundim

Considered the second oldest terrestrial language behind Aeonesti, Arenundim developed soon after the Disjunction of Order, when the Dwarves split off from their Elven cousins and began to form rigid laws and codes. The language itself reflects this shift, in both its spoken and written forms: highly ordered and logical, with precise syntax and complex grammatical rules, Arenundim was not only a stark departure from the flowing and fluid ancient Elven, but a rejection and repudiation of it. 
Arenundim survived intact after its codification by Koraxir, Dwarven Father, the unifier of the original Dwarven family, around 7600 BFR, until the Sundering of the Dwarves in 4622 BFR. The language remained, similar to Aeonesti, as the root and common form, but the three families of Dwarves took their own linguistic paths: Tuzutainim (Mountain Dwarven) and Dusterdorim (Hill Dwarven) sound somewhat similar to this day, but Duergarim deviates significantly and is more akin to Undercommon and even shares elements of Drow.
Arenundim and all three derivatives, however, use a form of Koraxicon, the fundamental Dwarven script.