Movements are the measure by which eras are divided in Rhydia. There are five that make up the history of the world.
The Movement Axion is a well-known and well-accepted bit of divine lore. First posited in the years after The Severence and codified after The Suture, it describes the idea that the history of the world can be divided into discreet "Movements," which begin and end when the world experiences a major cosmological shift. These cosmological shifts are accompanied by a change in the composition of The Symphony. Whether one causes the other or they occur simultaneously has always been a subject of debate.
In the beginnings of the world, magic flowed like water.
Following The Severence, the flow of magic was choked from the Material Plane. Much of the arcane energy in the world faded away and magic became much more of a rarity. To make up for this loss, the people of Rhydia began experimenting with technology. Compasses, printing presses, ship-building, black powder refining, lens grinding, and more all began during the Second Movement. For the first time, the people of Rhydia are able to safely navigate the seas between the islands now that storm and water elementals no longer lurk the open waters. And so, they do that en masse. Settlements are made, populations boom, and the first nation-states form.
The Suture undoes the magic of The Severence, and magic is able to flow freely again. The world begins responding to and experimenting with all of this newfound power and energy. It also means threats from beyond the Material Plane are now turning their eyes to new prey.
This is a time of arcanotech, nationalism, and war.
Following the Grimoire War, chunks of islands are raised into the sky. A cloud layer forms beneath them, and beneath that an eternally raging wild-magic storm. The surface of the world is unlivable. All life resides on the sky islands and navigates between them by airship. Magic is not flowing as freely as before, but not as little as the Second Movement. This is the end of the world. Will it end softly? Or forte?