"Everyone knows something about King Arthur. Whether you watched The Sword in the Stone as a kid, listened to Camelot as an adult, or just existed in a part of the world where Britain was briefly in charge, you know about King Arthur. But if you ever tried to look into King Arthur to try and find some sort of canon for the story, you were probably both confused and disappointed. Maybe you read somewhere that Merlin aged backwards, but then couldn't find any evidence to suppourt that. Maybe you wanted to know about the Holy Grail and ended up reading 50 pages about some Fisher King guy instead. Maybe you wanted to learn the sordid history of Arthur and Morgan Le Fay's secret tryst that famously produced the traitorous Mordred, and were utterly baffled to find zero connection between Mordred and Morgan at all. Whatever the case, while Arthurian mythos is very widespread and most people have at least some knowledge of the basic structure of the story, when you start tugging at the threads, the entire setup starts to lose cohesion. So what is Arthurian canon, and, more importantly, do we actually care?"
— Overly Sarcastic Productions, "Legends Summarized: King Arthur"
