Unishad

Unishad is a language that once was a very well-used language, which would later be replaced with Common, as the language of humans was simpler to learn. It's speculated that Unishad was an early precursor to the elven language, but there are very few similarities between the two that can be found. The reason for the theory is that they share a very melodic sound, which makes it sound as though the speakers are singing when they speak the language. However, that is where the similarities end.
Supposedly, Unishad was gifted to the mortals by the gods a long, long time ago, as a way to connect with each other. It was a reward for their help in defeating The Evil One, for the great sacrifice that they made after being made mortal by The Evil One, continuing to fight despite the very high risk that they would be annihilated.
But Unishad was lost to the mortals centuries ago. It is said that the mortals lost the right to speak this shared, divine language after the Great King revolted against the gods, making the gods leave the mortal plane and taking their language with them.
Although there is nobody around to write texts in the old tongue, texts from the past have been unearthed by archaeologists and researchers. There have been found as carvings on stone, engravings on jewelry, and letters. The meaning of these texts is still mostly a mystery.
A few scholars that have dedicated their lives to deciphering the language do exist, though there are still no fully comprehensive dictionaries, and the different scholars seem to disagree on many meanings. The scholars don't often get along because of this, and as a result, deciphering the texts seems impossible in current times.
It is said, however, that there is a folk in some forgotten part of the land that still speaks the language fluently. This is based on findings of items that seem to be too new to have come from the times when the Unishad was commonly used, but it is still simply a theory.