What Tolkien was really inspired by was Norse, Gaelic and Germanic mythos. Not to forget Middle and Old English Poems.

Norse:

- The Poetic Edda

- Prose Edda

- Beowulf

- Volsung Saga

Middle English:

- Pearle, (The concept of The Ring being "My Precious")

Welsh:

- Culhwch and Olwen, inspired Beren and Luthien (Silmarillion)

- Red Book of Herghest (Welsh Vellum) directly inspired Red Book of Westmarch

Finnish:

- Kalevala (Story of Kullervo) inspired Children of Hurin (Silmarillion)

German:

- Nibelungen and later work Der Ring Des Nibelung, inspired The One Ring and the myth of Broken Sword reforged.

Norse:

- The names of Gandalf and the 12 dwarves are directly taken from Prose and Poetic Edda

- High Elves / Gray Elves are inspired by Norse Calaquendi / Moriquendi

- Balrog and the Bridge of Khazad-Dum are direct allegory to norse fire giant Surtur and the Birfrost (recently depicted in Thor: Ragnarok)

Celtic:

- The Elves of Middle Earth (exiles) are based on Celtic fae gods, the Tuatha-de-Danan

References:

- https://en.wikipedia.org/wiki/J._R._R._Tolkien%27s_influence...