Amarthias, also called the Amarthian Language, is an ancient language descendant from the Ancient Kingdom's language. It is mostly unused in today's world with the exception of magic incantations, although it was once the native language of Kingdom of Morith before being replaced by the modern Ethrosian. Amarthias is now a language restricted to scholars and mages. Amarthias has the same subject-verb-object structure that Ethrosian has. However it has a vastly different dictionary. Despite being based on Ancient Amarthias, the two languages share a different alphabet, meaning a speaker of Amarthias cannot read Ancient Amarthias
When the Ancient Kingdom fell, written language fell along with it (in most areas). The last remains of the written language vanished about two hundred years before Morith. The spoken component however, survived for centuries after the fall of the old kingdom. After Morith was founded in 0 AM, a the language of the Vehra tribes was standardized into the Amarthias language.
Amarthias was eventually replaced with Ethrosian, which is near-identical to our own English, sometime in the seventh century. It remained a common language in the Vehra up until the tenth century, but was never widely spoken in the western or southern kingdoms outside of mage circles.