As reported by engadget,
Fragments of the Isu language have appeared in the games for over a decade. However, Assassin’s Creed Valhalla, the latest entry in the series, includes several translated documents players can read in the game’s modern-day segments. These allowed fans to start deciphering the language. What they found is a complex language that has its set of rules on verb tenses, grammar and conjugation, and it has more in common with Latin and Ancient Greek than any modern language. The video goes into almost exhaustive detail, and shows what the community learned from those documents can be applied to other sections of Isu text found throughout the game. Darby McDevitt, Valhalla’s narrative director, praised the team for what must have been a monumental effort.
And there’s more on the way. The above video is only the first of several clips the community plans to upload in the near future on subject. They’ll have another clip detailing the language’s numerical structure, as well as one on the Canterbury file, a long cursive text within the game that hadn’t been translated yet. You can follow along by subscribing to the Access the Animus YouTube channel.