Warner Bros. is slowly but surely beginning its return to Middle-earth, after the studio and Peter Jacksons primary adaptations ofLord of the Rings came to an end with the conclusion of theHobbit trilogy in 2014. But before we begin in earnest to see the studio return to one of its enduring cinematic successes with a bevy of spinoffs, were kicking off with perhaps one its most experimental and fascinating gestures: an anime adaptation of a tiny piece of Tolkiens vast chronology. That movie is, of course,War of the Rohirrim, set to hit theaters next month on December 13. Following the legacy of the famous king of Rohan Helm Hammerhand, the films overall narrative gives us an interesting bit of insight into how Warner will plan its futureLord of the Rings franchising in films likeHunt for Gollum and beyonda kernel taken from Tolkiens many, many writings, embellished and expanded upon to fill a full-length feature. If you dont know your Hmas from your Haleths, or your Dunlands from your Westfolds, heres what you need to know about War of the Rohirrim, and its connections to both Jacksons beloved movies as well as Tolkiens original works. When IsWar of the RohirrimSet? Warner Bros. The events ofWar of the Rohirrim take place around 183 years before the events ofThe Two Towers, setting it firmly within the events of the Third Age of Arda. We dont know an exact year as far as the chronology of the Jackson films is concerned, becauseFellowship of the Ring condenses an extended period of time from the novel, but in Tolkiens writing, the events laid out in the broad narrative are established as taking place around the years 2758 and 59, roughly 265 years before Two Towers.We dont know much about that period of time in either the cinematic continuity or in Tolkiens appendices, but from what wedo know in the latter, its a particularly dark time in Middle-earth. The rebellion of the Dunlendings against Helm Hammerhands rule comes during a devastating season known as the Long Winter, a five-month period of extreme cold and snow that not only caused mass death and famine across Eriador (including in the Shire, where Gandalf made himself known to the Hobbits in order to aid them through the crisis), but compounded struggles across two of its most important kingdoms in Rohan and Gondor. While the Rohirrim were besieged by Dunland, Gondor faced its own war with the Corsair pirates of Umbar and the Haradrim, with the dual conflicts and bitter blizzards isolating each kingdom from aid. Who IsWar of the Rohirrim About? Warner Bros. The films central conflict is built around two primary families. First, the House of Eorl, lead by Helm Hammerhand, the then-king of Rohan. Second, the family of Freca, a prominent Rohirrim lord who was descended from the blood of both the Dunlendings, the human neighbors of the Riddermark, and the House of Eorl itself, claiming an ancestral link to King Frawine, who ruled Rohan around a century prior. On Helms side, we know his three children will appear in the filmhis two sons, Haleth and Hma, and his daughter, who goes unnamed in Tolkiens writings around the event but is named Hra inWar of the Rohirrim. On Frecas, we have his son Wulf, who becomes a the leader of the Dunlending rebellion after his fathers death.Given that it is several hundred years before the events ofLord of the Rings, not many familiar faces play a prominent part inWar of the Rohirrim, but we know of at least two figures from the films who will return. Miranda Otto will reprise her role as owyn, serving as a narrator and framing device for the primary story of the film, and Sarumanwho, in Tolkiens writing, is just getting set up in Isengard around the time of these eventswith recordings of the late Christopher Lee used to provide his dialogue. How Much ofWar of the Rohirrim Comes From Tolkien? Warner Bros. Everything we do know about the loose events of the film is taken in part from a fraction of Tolkiens appendices forLord of the Rings. The bulk of the details of the life and (spoilers for events first told in nearly 70-year-old novel) death of Helm Hammerhand are covered in the appendices included in the back of The Return of the King, specifically Appendix A, Annals of the Kings and Rulers coverage of the House of Eorl and the lines of Rohans kings, and several small details from Appendix B, The Tales of Years as well asThe Two Towers itself. The story of the Dunlending rebellionspurred by Helms rejection of a marriage proposal by Freca to unite Helms daughter and Frecas sonis covered in just a handful of pages of material.While the appendices gives us the broad narrative structurethe reason behind the rebellion, Rohans invasion by Dunland, Helms retreat to the fortress that he would lend his name to, and the eventual rallying of the Rohirrim by Helms nephew and successor to the throne, Fralfits clear War of the Rohirrim is going to add much of its own material beyond simply adapting the tale as-is, especially in terms of offering more of the perspective of Hra, who is only briefly involved in the details covered in the appendices, compared to her driving role in the film. Although its the first time the character has been explicitly named, its not the first time shes appeared in an adaptation: Helms daughter briefly appears during the events of the 2017 gameMiddle-earth: Shadow of War, which, in a wild turn, sees Helm Hammerhand eventually transform into one of the nine Ringwraiths, killing his daughter in a fit of rage after liberating her from a rival warlord. Suffice to say weprobably wont see that happen here. Want more io9 news? Check out when to expect the latest Marvel, Star Wars, and Star Trek releases, whats next for the DC Universe on film and TV, and everything you need to know about the future of Doctor Who.