I've been reading a book on Irish Mythology (Lady Gregory's compilation) and it reads a lot like LoTR
Tolkien came up with new stories and characters, but the style is similar (and of course with sources from Norse Mythology and others, that mixed and grew apart, etc)
I very much recommend Tom Shippey's Road to Middle-Earth, which discusses Tolkien's influences from the perspective of a contemporary and friend and academic colleague.
Tolkien came up with new stories and characters, but the style is similar (and of course with sources from Norse Mythology and others, that mixed and grew apart, etc)