Andre Grandier is a central figure in The Rose of Versailles, known primarily for his unwavering loyalty and deep, tragic love for Oscar Francois de Jarjayes. His background is that of a commoner who was raised within the privileged world of the French nobility. Born in a village on the Jarjayes family estate, he lost his father at a young age and was raised by his mother. After her death, his only remaining relative, his grandmother who served as Oscar's nanny, took him in. This position allowed him to grow up alongside Oscar, the sixth daughter of a general who was raised as the heir to the family. From childhood, he learned fencing and horsemanship with her, creating a bond that transcended the typical master-servant relationship, though his grandmother often scolded him for forgetting his lower social standing.

Physically, Andre is described as a handsome young man. While his appearance varies across different adaptations, he is most commonly depicted with medium-length brown or black hair, often tied back, and green or blue eyes. He has a lean but capable build, reflecting his training as a soldier and swordsman. His personality is multifaceted. On the surface, he can appear somewhat goofy, laidback, and possessing a subtle, dry sense of humor. He is not afraid to speak his mind to Oscar, sometimes chiding her or offering blunt advice in a way few others dare. However, this casual demeanor masks a deeply sensitive and passionate nature. He is profoundly loyal and protective, his entire world revolving around Oscar. Beneath this devotion lies a constant, simmering anguish caused by his unrequited love for her and the rigid class barrier that makes their union seem impossible.

Andre’s primary motivation is his love for Oscar. This love is the lens through which all his actions are filtered. He serves as her most trusted confidant, her second-in-command, and her protector. He follows her from the gilded halls of the Palace of Versailles to the bloody streets of Paris, rarely questioning her decisions, as his devotion supersedes all else. He is tormented by his low status as a commoner, a member of the Third Estate, which forbids him from marrying a noble. This inner conflict, the struggle between his consuming desire and the impossibility of its fulfillment, defines much of his emotional journey. He is also a vocal sympathizer with the common people's plight, and his own experiences with suffering and injustice inform his worldview, making him a figure who bridges the gap between Oscar's noble world and the revolutionary fervor building outside it.

His role in the story is inseparable from Oscar's. He is her shadow, her anchor, and eventually, her equal partner. One of the most defining events in his life is the loss of his left eye. In a battle against the criminal known as the Black Knight, he takes a whip strike to the face while trying to save Oscar. Defying his doctor's orders, he removes his bandages to go to her aid, resulting in permanent blindness in that eye. The strain on his remaining eye causes his vision to slowly and cruelly deteriorate, leading to total blindness by the time of the French Revolution. Despite this disability, he remains fiercely determined to fight by Oscar's side.

Andre’s most significant relationship is, of course, with Oscar. They are childhood friends, commanding officer and subordinate, and eventually lovers. He knows her better than anyone, often understanding her thoughts and feelings before she acknowledges them herself. Their relationship evolves slowly and painfully from a childhood friendship into a deep, silent, unrequited love on his part. He suffers greatly watching her infatuation with the Swedish Count Hans Axel von Fersen. It is only later, when both have committed to the revolutionary cause, that Oscar admits she loves him in return. Their happiness is tragically brief; they share only one night of passion as mutual lovers. The very next day, Andre is struck by a stray bullet while shielding Oscar during a battle, dying in her arms. His death is a pivotal, devastating moment that precedes Oscar’s own death shortly after.

In terms of abilities, Andre is a highly capable soldier. He is an expert fencer and an excellent horseman, having trained alongside Oscar since childhood. These skills make him a formidable guard and a valuable training partner for her. He is also a competent tactician and a brave fighter, never hesitating to place himself in harm's way. His most notable abilities, however, are not martial but emotional: his immense capacity for loyalty, patience, and self-sacrifice. Even as he goes blind, his determination to protect Oscar never wavers, a testament to his strength of will and the depth of his devotion.