After the Sundering, humanity clings to huge floating islands, known as the Aether Sphere. The main known island nations are:
The Frisian Empire: the most powerful empire in the sphere, formed from a powerful trader nation. The Frisian fleet is a common sight across the sphere, as they provide the merchantile life blood but never mistake them for mere traders - they are a powerful military force as well.
Iberia: A noble, tradition-laden kingdom, dominated by the anti-aether Inquisition and their quest to avoid another Sundering by the abolition of all technology. The experts in clockwork technology.
The Lombardi Archipelago: A series of small islands linked with bridges, chains and other tethers. Each island is a smaller city state and as a whole they are wracked with conflict and strife. The politics of the Lombardis is legendary. Should they ever stop trying to topple each other, they might be able to leverage their amazing shipyards and universities to become a true power in the sphere. The home of aether technology.
Gallacia: An old-fashioned kingdom with a strict and complex social order, a comprehensive code of honour and a deep-seated distrust of the Frisians, who they see as stealing their role as the central power of the sphere.
The Teuton Massiv: As near to an industrial complex as the sphere has, the Teutons are an insular, secretive nation ruled over by a council of barons. The Teutons are the masters of military development and their fleet is the strongest in the sphere - although they have never been successful in deploying it as they are beholden to a series of treaties and agreements that hold them in check.
Berbary - the Berbari are a mix of many different people who have banded together under one flag and one principle - if I can sell it, I will get it. The Berbari are the ultimate opportunists, sailing the sphere and gathering whatever they need to survive, through means legitimate or illegitimate. Many people call them simply pirates, but that is far from what they are.
The Spire: Not a true kingdom, the Lady of Masks' city exists as a freeholding for all ships, all people and all ventures. She cares little for the politics of the major kingdoms and the arguments of noble houses. She simply wishes for her city to the a safe space for traders and pirates to come together.