|“||The world of Baten Kaitos is a world adrift in time and space. Humanity forges its existence on an archipelago of land floating in a yawning, endless sky. The earth below, and the vast oceans it once harbored, are mere legend.||”|
—Retail Description of EWatLO
The Baten Kaitos series takes place in a world where humanity lives on a series of island-nations in the sky. These islands are the last livable remnants of a poisoned Earth that was devastated a thousand years ago in the War of The Gods. Magic was once prominent before the Era of the Sky, however over the years the art was lost to much of the populace of the Baten Kaitos world, with only isolated peoples such as the Witches of Wazn and the Children of the Earth still practicing it regularly. Most of the world's population have developed Wings of the Heart, a physical manifestation of the human spirit, to help them in their everyday lives. Various technologies have been developed over the years as well, including Magnus, a technology allowing the "essence" of an item to be sealed in a card-like object for easy transportation, and Machina, machinery designed to replace the need for the power of the heart. There also exists a strange pocket dimension which encompasses the island of Mira and other mysterious powers such as Wiseman and the Dark Brethren left unexplained in series proper. By the end of Baten Kaitos, the ocean is restored and the Age of the Ocean begins.
An approximately 1000 year span in the history of the world of Baten Kaiots is featured in the series through three eras. Very little information about prior to these eras is given outside of implied history in various Magnus descriptions.
- The Age of the Gods was a time when humans still lived on Earth. It was brought to an end with the War of The Gods.
- The Age of the Sky lasted for 1000 years as humanity dealt with an existence in the Sky. The Return to Earth marked the end of this age.
- The Earth, once home to a great Ocean, is mostly barren and polluted in the Age of the Sky. Besides the Ocean and the continents that were lifted into the sky, the Earth is comprised of two major, known continents: Duhr and the Age of the Gods.
- The Sky is comprised of the Five Great Nations and a variety of smaller islands and areas located in the sky. The Five Great Nations arose when five continents lifted into the sky after the War of The Gods by the power of the End Magnus. They are now the largest world powers and consist of Sadal Suud, Diadem, Anuenue, Mira, and Alfard. Lesser features in the skyscape are Wazn, Hassaleh, Coliseum, Celestial Alps, Nekkar Quietlands, Endmost Bethel, Greater Celestial River, Trail of Souls, Taintclouds, Sedna and Tarazed, which levitate for a variety of reasons.
- The Outer Dimension is one or a collection of worlds that exists parallel to the Earth and Sky. Various entities emanate from it, including Guardian Spirits, the Dark Brethren and various Monsters. Mira is known to fluctuate between it and the known world and various locations along the border between the two are seen, such as the Portal to an Outer Dimension and Interdimentional Cracks.