From advertisements to amusement parks, themed restaurants, and Renaissance fairs twenty-first century popular culture is strewn with reimaginings of the Middle Ages. They are nowhere more prevalent, however, than in the films, television series, books, and video games of speculative genres fantasy and science fiction. Peter Jackson's The Lord of the Rings and The Hobbit film trilogies and George R. R. Martin's multimedia Game of Thrones franchise are just two of the most widely known and successful fantasy conglomerates of recent decades. Medievalism has often been understood as a defining feature of fantasy, and as the antithesis of science fiction, but such constructs vastly underestimate the complexities of both genres and their interactions. Medieval has multiple meanings in fantasy and science fiction, which shift with genre convention, and which bring about their own changes as authors and audiences engage with what has gone before in the recent and deeper pasts. Earlier volumes