I only know the bare bones of the Arthurian myth and legend outside of Bernard Cornwell's The Warlord Chronicles (check it out if you're into that kind of stuff, it's a wonderful trilogy), which takes the story of King Arthur, strips away the magic, and uses it as the backbone for the story of the Saxon invasion of Dark Age Britain in the late 6th and early 7th centuries.
Kabam used the tale of King Arthur to drive its userbase, and is very proud of the number of players their free-to-play browser and mobile strategy games, Kingdoms of Camelot, and Kingdoms of Camelot: Battle for the North, bring in. That's cool. What's not cool, Kabam, is using a pretty fresh Game of Thrones spoiler as your point of reference for comparison.
Kabam has polled their player pool and used the data to built this very nice infographic. Check it out.