She-Ra – Princess of Power debuted in 1985 and we soon learned that her alter ego of Princess Adora was the twin sister of Prince Adam/He-Man. She-Ra was intended to appeal to young girls in the same way that He-Man appealed to young boys. She was introduced in the animated movie The Secret of the Sword as Force Captain Adora, a member of the Evil Horde that rules the planet Etheria. Princess Adora discovers that she is the long lost twin sister of Prince Adam of Eternia, having been kidnapped as a baby by the Horde’s leader Hordak. She is granted the Sword of Protection, which parallels He-Man’s Sword of Power, gaining the power to transform into She-Ra, her secret identity.
King Randor and Queen Marlena from planet Eternia, had twins, a girl and a boy named Adora and Adam. Hordak, leader of the Evil Horde, kidnapped Adora and escaped to Etheria, where Adora was raised as a mind-controlled Force Captain of The Horde. Adora’s uniform – which she continued to wear throughout the series, even after defecting to the Rebels – consisted of a red leotard with long white sleeves, matching boots and gauntlets, and a black belt.
The Sorceress sent Adam and Cringer to the planet Etheria to give the sword the Sorceress gave him to Adora. The Sorceress reveals to Adora that she was kidnapped by The Horde when she was a baby and that she had a twin brother. By repeating “For the honour of Grayskull” she is transformed into She-Ra. She releases He-Man and jumps from a window, crashing into the Horde stables, landing atop Spirit who is transformed into Swift Wind, a winged talking unicorn. They fly ahead to warn The Rebellion. He-Man and She-Ra return to Eternia, but she decides she must return to Etheria so that she can help free the planet from the Horde oppression.
Adora, having been trained by the Horde her entire life, assumes leadership of the Great Rebellion. The epic battle to free Etheria from the grip of the Evil Horde rages on, spreading across the corners of the planet. Through this war, She-Ra calls upon her allies across the globe, using their special talents to battle against Horde creations. Whether or not She-Ra and her forces were ever successful in defeating the Horde was never revealed.
When Adora transforms to She-Ra, two castles are shown in the background. The first is Castle Grayskull. The second is the Crystal Castle. The Crystal Castle is located at the top of Skydancer Mountain and is overseen by an entity called Light Hope, who advises She-Ra in times of crisis. It should be noted that the Crystal Castle’s location is known only to Argo (the King of Trolls), She-Ra, and He-Man (she brought him there one time); She-Ra has sworn to secrecy its location, thus earning the title of “Defender of the Crystal Castle.”