Cataclysm

''Hundreds of years ago, advanced cultures thrived on Novia. But then the moons were shattered, which started a large celestial event that caused a global apocalypse. Civilization was destroyed, but not everyone was killed. Thanks to foresight, hardiness, or luck, a few people were able to ride out the catastrophe and rebuild in the chaos that followed.'' - Thibodeaux

Developer Quoted Lore

 * Among the truths you will learn is that much of our knowledge of the land of New Britannia is lost to the ages. The survivors of the Cataclysm four centuries past have settled in the land we call “Novia”, a large island which, while bearing the scars of that time, still harbors enough life to support our people. And others, as well… many of which you will meet on your travels.

Trivia
Old Britannia had two moons: Trammel and Felucca.