Etheria the brother planet of Eternia, is ruled by Hordak, a leader and member of the Horde of Evil.
Etheria has often been linked to Eternia through the use of dimensional portals opened by The Sorceress, and its people are descendants of Eternian immigrant colonists.
At a glance Etheria appears to be a beautiful, lush, fantastical world. And while this is indeed true, in reality, it is also a dystopia plagued by the tyrannical rule of the Evil Horde, which invaded the planet long ago and conquered it. However, due to the continued efforts of The Great Rebellion, the planet is slowly but surely becoming more and more liberated.
- Main article: Timeline of Etheria
Etheria was founded by a group of beings known only as The First Ones. Their living spirits dwell in the Cavern of Fire, located in an underground kingdom, beneath The Crystal Castle. These beings were spiritual who connected the planet brother Eternia and other planets in which it attracted the spirit of Grayskull, Light Hope, (former member of the guardians of Castle Grayskull) of Eternia to unify, creating dimensional portals, where a caravan of Eternians immigrated to this planet, founding Etheria.
When the Horde invaded Eternia, Hordak was defeated by the King of Grayskull, casting Hordak and his allies into the dark field of Etheria, which had a direct passage to the planet, where Hordak takes his possession as the tyrant of the planet, Hordak uses the dark field to have contact with Skeletor linking his fortress near the serpent mountain, his ancient throne.
The headquarters of the Horde is northwest of The Whispering Woods, where on the Horde's battlefield against rebellion, built its military barracks in the valley of shadows near the dark field.
About 300 years ago, Eternia and Etheria had a world war for dimensional demons, both planets had large advanced cities, but powerful parts like Grayskull Castle and Crystal Castle were preserved in the war. Ancient archaeological cities in medieval style have been used and refined to new technologies, as in the case of the Royal Palace of King Randor. In Etheria, the ruins of large cities, gave rise to the construction of colonies and royal palaces.
Years later, this connection of the portals opened a dangerous dimension, releasing the pernicious Gargh demons that invaded Etheria and Eternia, starting a world war on the two planets, the demons dominated the portals and destroyed the connections of various worlds, preserving only the connection between Eternia and Etheria, resulting in the colonization of Eternian survivors for Etheria after war. Only Trolla has preserved part of the remaining portals against the Gargh, one of them goes towards Earth
Cities and Towns
Brigis Village - a village that was voluntarily put under a spell that keeps it prosperous forever, but makes it only appear on Etheria for one day each five hundred years.
Devlan - A small village similar in appearance to Thaymor, but more secluded.
GaleBreath - A town whose members joined the rebellion after hearing Adora speak.
North Land - A town where the Horde tried to start a re-education program where they burned books and taught children from a Horde-approved curriculum.
Outpost Six - A Horde controlled outpost that includes an Inn.
Rosewood - A farming community on which the Horde imposed heavy taxes.
Small Oak - A town where Horde scientists invented a shrinking serum.
Thaymor - A town near or in the kingdom of Bright Moon. It is the town Prince Adam first went to when he came to Etheria. It was also one of the first places where She-Ra organized a rebellion. It was the home of the Laughing Swan Inn.
Castles and Kingdoms
Bibbet Land - Home of the Bibbets.
Castle Bright Moon - A heavily fortified castle, which is the seat of power for a kingdom of the same name. It is ruled by Queen Angella, mother of Princess Glimmer. Queen Angella had extremely powerful magic powered by Etheria's three moons with which to defend the castle. This magic left the Castle vulnerable during eclipses.
Erelandia - Commonly referred to as King Duplis' Kingdom, this kingdom payed taxes to the Horde, but Prince Hazar secretly helped the rebellion. He was sent to the Mines of Mondor on the planet Krytis for his crime. After his son was rescued by She-Ra, King Duplis agreed to help the rebellion.
Halfmoon - Underground kingdom inhabited by the Magicats.
Mystacor - A magical kingdom ruled by Castaspella. The seat of power was a Castaspella's Enchanted Castle, which set atop a floating island. Many of its people are magically endowed. For a short time it was ruled by Mortella.
Mystacor Forest - A beautiful forest situated in Mystacor.
Beast Island - A dangerous jungle island that was seemingly made up mostly of rock and the fossilized skeletons of huge beasts. It was home to the Horde's main prison where it once held He-Man and the Dragon Sorrowful. Grizzlor was often in charge of the island.
Cave of Winds - a magical cave which can unleash unstoppable wind torrents.
The Dark Mountains - A mountain range which contained energy mines. Horde slaves would often be taken there.
Flower Mountain - a place of great beauty where the Day of the Flowers is held.
The Freezing Mountains - Between the Whispering Woods and the Valley of the Lost. Possibly part of Frosta's kingdom.
The Fright Zone - The headquarters of the Evil Horde, home to their factory-like base. A large cloud of brownish smog covers the skies above.
Lavender Pond - pond where Bow and Adora were to meet each other once.
Mystic Stones - an area where Bow was once encouraged to take a vacation.
Skyland - several floating islands inhabitted by Skylanders.
Valley of the Lost - A desolate waste land where the ancient Library of the Valley of the Lost is located.
The Whispering Woods - The home of The GreElat Rebellion. An enchanted forest, protected from the Horde by a spell.
Seas, oceans and rivers
There are twelve oceans on the planet Etheria.
Polar Sea - The coldest of Etheria's twelve seas.
Sea of Sigh - Octopus Cove is a port on this sea.