Here's why:
* Romance: The story focuses on chivalry, courtly love, adventure, and the supernatural.
* Mythology and Folklore: The core elements of the story, like the magical sword Excalibur, the mystical Lady of the Lake, and the quest for the Holy Grail, draw heavily from Celtic mythology and folklore.
* Medieval Setting: The story is set in a romanticized version of medieval Britain, with knights, castles, and courtly rituals playing significant roles.
* Heroic Tales: The story revolves around King Arthur, a virtuous and courageous leader, and his knights, who embody ideals of honor, bravery, and loyalty.
While the story itself is a romance, it's been adapted and interpreted in many different ways, leading to elements of other genres such as:
* Fantasy: Some versions feature elements of magic and supernatural creatures, making them fit within the fantasy genre.
* Historical Fiction: Some interpretations attempt to present a more historically accurate portrayal of the period, incorporating elements of historical fiction.
* Epic Poetry: The original tales of King Arthur were often told in epic poems, which often feature themes of heroism, adventure, and warfare.
However, Arthurian Romance remains the most accurate and encompassing genre for the story of King Arthur and the Knights of the Round Table.