Princess Allura was born and lived on Altea along with her mother, her father, King Alfor, and their royal advisor, Coran. During her father's life, the Alteans held an alliance with the Galrans. King Alfor built the Black Lion from the material found in a comet that collided with Zarkon's planet, and Zarkon became the Black Paladin. The origins and creation of the other Lions of Voltron is unknown, but Coran's grandfather built the Castle of Lions to house them. However, Zarkon sought to have the power of Voltron for himself so he betrayed Alfor and the Alteans, mercilessly attacking them with the might of Galra fleets. This led King Alfor to put Allura and Coran in a deep sleep inside cryo-pods within the Castle of Lions, and to scatter the Voltron Lions to hidden locations across the universe so they would not fall into Zarkon's hands. Alfor met his end by unknown means, and the Altean race was destroyed along with Altea and its entire solar system.
Altea was a planet blooming with the beauty of its purple juniberry flowers. The Altean race built a civilization with impressive technology seemingly unexplainable by science alone. Altea seemed to have several artificial megastructural rings encircling it, all equally separated from each other. It is unclear whether Altea's blue-colored surface was its diffraction of its atmosphere due to their star or that most of Altea was covered with oceans. Coran does not recognize the concept of rain, but claims that boiling hot rocks frequently fell from the sky.
- For more information, see the Alteans article.
The race of people native to Altea are called Alteans. They are aliens nearly identical to humans of Earth. Defining Altean features are pointed ears and sickle-shaped markings on each cheekbone, as well as pupils with a colored speck in the center. The markings vary in color by individuals, as do hair, eye, and skin color. The royal family is known to have a trait of silver hair in its bloodline.
The culture of Alteans remains largely unknown, but they appeared to be a morally-straight, well-intentioned race that valued diplomacy, protection of allies, and peace. Their currency was called "groggeries" which came in the form of Altean crown bills and was used by more races than their own. The groggery was named after "King Groggery the Infirm" and had his face printed on the bills.
- Having rocks as rain could be referencing models of exoplanet "Vaporized rock showers".
- Alteans can suffer from a harmless condition known as "the slipperies", where their bodies excrete extremely slick fluid to such an extent that walking is nearly impossible, as the Altean will likely slip, fall, and slide instead. The condition is common for Alteans of older age and usually only lasts a couple of days.
- "Sloven-day-ho" is Altean for "gone".