"The Leviathan Archipelago gets its name mainly from the many gargantuan, primordial fossils and bones strewn about the many, many isles. It also gets its name because many such leviathans still move between the isles; lurking within the dark, green depths.
Admittedly these seabeasts are mere minor shadows compared to the leviathan fossils, but one could be forgiven for believing that in the deepest abyss, such world-ending monsters could still exist; asleep and still, until the day someone is foolish enough to disturb them.
The islands themselves were only made known some 100 years ago, when they appeared out of the ocean mists common to the southern Stormseas of the Farthest East. Ximese sailors navigated the archipelago, and discovered the route to the continent of Kinthai, otherwise also known as Kildara to the non-Ximese world.
It didn't take long after until expeditionary fleets from the Old Verd arrived to claim what they could, but the sudden influx of so many different peoples led to the Leviathan Archieplago becoming quite lawless, which in turn gave rise to corsairs and pirates of the Vandressi Armada, who dominate the Sea of Leviathans."