Princess Emeraude is fictionaly character from Japanese manga/anime series Magic Knight Rayearth.
Princess Emeraude is the sovereign ruler of Cephiro and a Goddess-like figure whom all the inhabitants pray to for peace, prosperity, and protection. She is also the first person to summon Hikaru Shidou, Umi Ryuuzaki, and Fuu Hououji to the mystical, otherworldly realm of Cephiro, to become the legendary Magic Knights.
Little else is revealed concerning her nature until the climax of the first series, although she is highly loved by her subjects.
In the anime it is revealed that she was once a noblewoman of Cephiro, and had later used her power as the Pillar to prevent her younger brother Ferio from being punished for stealing something from her. He had forgotten she was his sister because, at his own request, she had used her magic to help him forget about her so he would not miss her or feel sorrow, and asked that she in turn forget him, so that she could focus her thoughts and prayers only on Cephiro. In the manga series, she is Ferio's older sister as well, but there is no mention of Ferio stealing something from her, and he does remember that she is his sister; in fact, he left the palace on his own will.
The Pillar of Cephiro must spend every waking moment of their existence praying for Cephiro's benefit, and when Princess Emeraude fell in love with Zagato the High Priest, she was constantly thinking of him and not Cephiro, and eventually imprisoned herself in a water dungeon (resembling a large peony in an underwater cavern beneath Zagato's court in her own palace) in hopes of being able to focus on only Cephiro. When she is unable to do so, she summons the Magic Knights. Zagato, who had in turn fallen in love with her, discovered Princess Emeraude's true feelings for him and visits her often, telling her that he does not care for the fate of Cephiro, and that there was only one thing in the world that he cared about – Emeraude herself. Believing if he destroyed the Magic Knights, he would be able to keep Emeraude safe and that by sheer will everything would turn out all right, he sent his minions one by one, each one failing to carry out the task.
When the Magic Knights awaken the Rune Gods and arrive at the palace, Zagato is waiting for them. He confronts them in a Rune God he created with his own will to kill them and protect Emeraude, intent on making his one desire come true. But the Magic Knights emerge triumphant and kill Zagato. Emeraude, devastated by the loss of her beloved, collapses under the tremendous weight of her own guilt and grief. Transforming into an older- and more sinister-looking version of herself, she breaks free from the water prison. This form is only filled with anger and pure hatred for the Magic Knights for killing Zagato, forgetting it was she who summoned them in the first place.
Zagato's court begins to fall apart beneath her anger, and she dons her own Mashin and grabs Zagato's fallen sword. She begins to fight the Magic Knights in their Mashin, and they see fleeting visions of the real Emeraude who tells them of her plight and how she has realized that it would be better if she died than tried to rule Cephiro with a heart tainted with grief and regret. No one of Cephiro is allowed to kill the Pillar and the Pillar cannot will itself to die, so the "girls from another world" (the Magic Knights) are there solely for that purpose: to don the Mashin and kill the current Pillar of Cephiro, as death is the only way for the Pillar to abandon their duty.
The Knights resist at first, but tearfully give in when Emeraude begs them to send her to "where she may think only of Zagato" and be with him. Emeraude dies, using the last of her power to send them home to the exact moment they disappeared from Tokyo Tower. The last image of her they see is her purified adult self in Zagato's arms, smiling sweetly and thanking the Knights for granting her last wish.
It has been speculated that Princess Emeraude was based on The Childlike Empress from Michael Ende's The Neverending Story (Die unendliche Geschichte), being as they are both directly linked to their kingdom (if one should die, so shall their empire), they both do not play a direct role despite the fact that their powers are the most revered, and they are both depicted as young women, no older than the age of ten to thirteen. Furthermore, though they are both young in appearance, they are both considered "ageless". Lastly, their stories, though different in ways, are also similar. Recalling the fact that Emeraude sent for earthlings to kill her (for no one in Cephiro could do her harm), The Childlike Empress sent for a human boy, for no one in her kingdom of Fantasia could give her a new name. Also the Proof of the Pillar which took the form of Emeraude's tiara could also be related to The Childlike Empress' AURYN, which was the symbol of her absolute power in Fantasia.
Sometimes known as Princess Esmerald or Esmeralda, and misnamed Princess Emerald in the official English translation of the Tsubasa: Reservoir Chronicle manga. She gets her name from the Mitsubishi Emeraude.