King Arthur was a legendary British king who may or may not have been a real person from around 1,500 years ago. According to the famous stories, Arthur proved his right to be king by pulling a magical sword called Excalibur from a stone, something no one else could do. He ruled from a castle called Camelot and gathered the bravest knights in the land at a round table, where everyone sat as equals.

The stories tell of Arthur's wise advisor, the wizard Merlin, and the Knights of the Round Table, who went on quests to help people and fight evil. These knights followed a code of chivalry, meaning they promised to be brave, honest, and protect those who couldn't protect themselves. The most famous knights included Sir Lancelot, Sir Galahad, and Sir Gawain.

Historians debate whether Arthur really existed. Some think he might have been a military leader who fought against invaders in Britain after the Romans left. Others believe he's entirely fictional. Either way, the Arthurian legends have inspired countless books, movies, and stories for over a thousand years. When people talk about King Arthur today, they usually mean the legendary figure from these tales: a noble king who tried to create a kingdom based on justice and honor, even though his dream eventually fell apart because of betrayal and war.