Well, initially, the king arthur origin stories were likely just local legends in Britain. As time passed, different cultures influenced them. For example, the Norman invasion brought new ideas. Writers and bards started to expand on the basic story of Arthur's origin. They added details about his family, like his relationship with Merlin. The idea of Arthur as a great king ruling over a noble kingdom grew. Also, the legend spread across Europe, and different regions added their own twists. In France, for instance, they emphasized the courtly love aspect which changed the perception of Arthur's origin story in some ways.
The development of King Arthur's origin stories is a long and complex process. In the early days, the stories were probably just fragments of folklore. As the story was told and retold, new elements were incorporated. The Arthurian legend became a way to explore themes like chivalry and heroism. The origin stories evolved to include his relationship with Guinevere and Lancelot. This added a layer of drama and romance to his origin. As literature became more developed, especially in the form of the great Arthurian romances, the origin stories were further refined and expanded. They became not just about a king but about a whole world of knights, magic, and noble ideals.