Heroes on quests are common. Sometimes, The Hero's motivation for pursuing the quest derives from his regard for some sort of idealized woman. Not uncommonly, this lady is the hero's love interest, and he is striving in order to be able to marry her. His love for her is pure and strong and overcomes all temptations that are thrown into his path.
The lady herself often occupies an exalted role: she is a goddess, a saint, a queen, a princess, or something similar. Generally, she is very pure, sometimes to the point of seeming unapproachable. If she is unmarried, she is chaste. She is also often a Proper Lady. If it's not just the fact that she's inspirational, but that he feels like she's above him, she's a Peerless Love Interest.
The lady can be the one who gives the hero his quest; he then departs to complete it before returning to her. Alternatively, she flits in and out of the hero's path, reminding him of her presence but staying out of reach. Occasionally, she is at his side all along, serving as a reminder of what he is striving for and inspiring him to persevere. In all situations, she often dispenses advice to the hero, although that advice can be rather cryptic.
This trope is particularly common in works from the medieval and Renaissance period, as it ties closely to the ideas of the Courtly Love tradition. In older works, it often takes the form of a knight errant and his lady love.
Compare to The Mentor, The Lost Lenore, Manic Pixie Dream Girl, and Men Act, Women Are. Called "Meeting With The Goddess" in Joseph Campbell's The Hero With A Thousand Faces. When the hero's muse is another hero, it's The Knights Who Say "Squee!".
- Kisara, the vessel of the White Dragon in Yu-Gi-Oh!. She provides an almost literal light to balance Priest Seto's inner darkness, and her Heroic Sacrifice and death in his arms provides the inspiration for his reign.
- Rem in Trigun inspired and guided the main character, Vash. She's the reason he never kills anyone, no matter how much they deserve it. She took Vash and Knives in as her own children when the crew found them, and acted as their surrogate mother. She is extremely kind and idealistic, and Vash treats her lessons and worldviews as sacred.
- Miu in Kenichi: The Mightiest Disciple. She's the granddaughter of the World's Strongest Man, and she's always been a better martial artist than Kenichi, who makes it his goal to be strong enough to protect her.
- Deconstructed by Osamu Tezuka in Barbara, released during the peak of his Gekiga period. The Hero's Muse is no idealized woman but an alcoholic, filthy, and rude prostitute (still a Shameless Fanservice Girl), yet she's explicitely refered to as a muse since she embodies everything that inspires an artist. Plus, she actually IS a Greek muse. She also counts as a parody of the Manic Pixie Dream Girl.
- In Saint Seiya, the Anti-Villain Cassios sees his master Shaina as his inspiring muse since she was the one who taught him how to fight. Even more meaningfully, he commits a Heroic Sacrifice to spare Shaina the pain of losing the man she loved, Seiya. As he's about to pass away in Seiya's arms, Cassios explicitely calls Shaina his "inspiring muse".
- The soldiers in Mulan discuss this trope in the song "A Girl Worth Fighting For".
- In A Knight's Tale, Jocelyn is the noblewoman who has never been unhorsed.
William: Your name, lady. I still need to hear it.
Jocelyn: Sir Hunter, you persist.
William: Perhaps angels have no names. Only beautiful faces.
- In the 1977 film Julia, the title character essentially fulfills the trope. The twist is that the main character being inspired to action is also female and both of them are presumably heterosexual.
- The powerful and mysterious Sisters of Orion in Alterien serve this purpose for Oberon.
- In Astral Dawn, the Mayan goddess of the moon, Ixchel, literally serves this purpose for Caspian. She's also his love interest.
- Dante of The Divine Comedy is sent on his quest for redemption through the afterlife by Beatrice, who enlists the help of the poet Virgil to guide him through Hell and Purgatory, and guides Dante through Heaven herself.
- In the first book of The Faerie Queene, The Redcrosse Knight is guided and inspired by his love, Una, who is the personification of the "true church".
- In Stardust, the main purpose of Victoria is to motivate Tristan to go into the fairy world. It is then subverted by having her not be important thereafter.
- In The Lord of the Rings, Arwen functions in this role for Aragorn: the driving force behind his striving to regain his crown is his love for Arwen and the fact that he can only marry her once he is king.
- In Don Quixote, the eponymous hero fights for his lady love, to whom he refers as Dulcinea. In his mind, he elevates her to a princess and the most beautiful woman in the world, although she is in reality a peasant girl named Aldonza.
- In The Golden Ass, the protagonist, Lucius, after searching long and hard for a way to reverse his transformation into a donkey, is finally inspired by the Egyptian goddess Isis. She reveals herself to him in a vision and teaches him the steps to change back into a human. Having fulfilled his tasks, he joins the Cult of Isis and devotes himself to her.
- Subverted in "Eutopia" by Poul Anderson: the protagonist is on the run and only keeps going due to his dreams of his lover Nik, who turns out to be a boy.
- In Deryni Checkmate, (then) Countess Richenda of Marley is this to Alaric Morgan from the first time he sees her. He dreams of her for months afterward, and is finally introduced to her by Kelson during preparations for the Torenthi campaign in High Deryni. She lampshades this trope just after they share a Mind Link: "Then I have given you that much more to fight for." After their marriage, she also inspires him to fill the gaps in his arcane education, passing on much of her own Eastern-influenced training to him.
- Forever Gate: Ari, his daughter, is the inspiration for all of Hoodwink's actions. As this involves pulling him into her freedom fighter activities, she invokes this trope to ensure his assistance.
- Babylon 5 has Delenn for John Sheridan in the back half of the fourth season, when they are separated on their separate quests (hers to help rebuild the fractured society of the Minbari, Sheridan to overthrow the corrupt President Clark and restore a real democracy to the Earth Alliance). Unlike most other examples, they're already engaged to be married, but can't do so until the galaxy is no longer about to fall apart around their ears.
- Space: Above and Beyond: Nathan West joined the Marines in hopes of being deployed to the new colony that his girlfriend had gone off to (West was supposed to go as well, but got pulled at the last second). Soon after, a war breaks out with a newly discovered alien race, and the colony is captured. Everyone in the Wildcards are determined to win, but they note that only West's motivation is so personal.
- Doctor Who has touched on this a few times. Often the Doctor's driving motivation to help is the (usually female) companion he has with him at the time, either due to her encouragement or because she finds herself imperiled. Due to story-related reasons too complex to relate here, the 2005-2006 companion Rose Tyler and the 2012-2015 companion Clara Oswald at times satisfy the "idealized woman" aspect of the trope as well.
- In Chaosium's Pendragon, knights are expected to form this kind of relationship (called Courtly Love) with an appropriate lady.
- Warhammer: The Bretonnian knights, being Arthurian knights in France, follow the cult of the Lady, a mystical figure who gives visions and quests, leading to drinking from the Grail. Warhammer being the cheerful and happy place it is, the Lady may or may not be an elaborate hoax pulled off by the Wood Elves to protect their lands.
- In Spamalot, the ethereal, white-clad Lady of the Lake fulfills this role (romantic interest and all) for Arthur. Although, Monty Python being Monty Python, she's a bit less passive and pure than is usual, especially once she decides she's not getting enough screen time.
- Bioware games tend to have one good female character as a romantic option for the Player Character, and they tend to get upset with you if you do something For the Evulz. Obviously, these are Bioware games, so this trope can just as easily be Played Straight, averted, subverted (you Corrupt the Cutie), inverted (the player character could be the one who inspires), etc.
- Pit in Kid Icarus: Uprising is completely devoted to Palutena and stands beside her despite her constant trolling.
- Deconstructed in The ClueFinders Reading Adventures. Owen is Wrong Genre Savvy and looks to Princess Malveera this way for most of the game. Over the course of the game, Joni gradually realizes that there is something up with the Princess, but Owen refuses to see it until The Reveal. It turns out the Princess was just a disguise used by the Big Bad to take advantage of the Macguffin Delivery Service.
- Princess Yue, of Avatar: The Last Airbender: She is a princess who sacrifices her mortal life to become the moon spirit. In the episode "The Awakening", she provides encouragement and help to Aang at a time when he desperately needs it.
- Any time a woman is on the British throne, expect her to be invoked as this - all the way from Boadicea to Queen Victoria (this was especially prevalent in Queen Vicky's time), and even the current Queen.