@Papissama What basis is there for making the umbrella for the franchise be "Lord of the Rings". Sure, it's the flagship work, but it has always been portrayed as one piece of a larger whole. It's not even the first work, being a sequel to The Hobbit. And The Silmarillion and The Children of Húrin, among others, are largely removed from the story of the trilogy (seeing as how almost all of the players in the other books aren't even born yet, or even their realms founded). If anything it should be under a heading signifying this larger historical/mythological/literary work created by Tolkien, with it being done by him and focusing on the same canon being the unifying themes. The term I personally have always used is "Tolkien's Legendarium" which as far as I'm aware is fairly standard. "Tolkien's Mythology" or something along those lines would also be fine. "Arda" is the name of the world itself, if you want to be technical along those lines, though Middle-earth (the primary location, a supercontinent) is more well-known/used and so might be acceptable. But "Legendarium" is probably the most appropriate term, and as far as I'm aware is largely synonymous with Tolkien's work specifically. In any case all of these are better than just lumping the mythology under "The Lord of the Rings", which is really a relatively small piece of the canon, taken from a wider view. I know of no serious Tolkien fan who has used that term to describe the greater mythology.