Old Castanorian was the precursor to Common, and the language of ancient Castanor. Due to the efforts of the Castanorian Emperors in forging a single human identity, it rapidly spread to be the language of all humans in Cannor. It originated from pigdin mixture of Bulwari, Kheteratan language of the Castanites mixing with the proto-Escanni human and Dwarven tongue.
As the influence of Castan's Empire fell and the dominance of the Damerian Republic in the Dameshead the language eventually evolved to what we know today as Common. Dialects leaning closer to Old Castanorian is still spoken in a few remote regions in Cannor to this day, such as the Lorentish Flats and Marrhold, although it is mutually intelligible with Common.