Mythopoeia

Mythopoeia (also mythopoesis, after Hellenistic Greek  "myth-making") is a narrative genre in modern literature and film where a fictional mythology is created by the writer of prose or other fiction. This meaning of the word mythopoeia follows its use by J. R. R. Tolkien in the 1930s. The authors in this genre integrate traditional mythological themes and archetypes into fiction.