Thadrian is a regional language spoken primarily by the population of Thadria, including Viridia, Erenon, Forloroth & Valadhel, and Hkarzda. Thadrian's status as the court language of the Dominion of Viridia has given it a degree of prestige, and nobles and the wealthy outside of Thadria sometimes learn Thadrian in addition to their native tongue(s).
Thadrian is the only major language in the super-region of the Chaska Sea that is tonal in nature - the language is often seen as highly musical, and many songwriters and bards write and perform in Thadrian specifically to take advantage of the perceived beauty of the language.
Thadrian vocabulary is greatly influenced by Hellean, and vice versa, due to speakers of the two languages' long intertwined histories.