J.R.R. Tolkien left a wealth of published works behind, and it looks like Peter Jackson is determined to bring all of it to a movie screen near you.

The Lord of the Rings: The War of the Rohirrim, the first of several new films based on the venerable author’s Middle Earth stories to be released. It’s based on the legend of the King of Rohan, included in the appendices of the Lord of the Rings books.

Set 183 years before the events chronicled in the original trilogy of films, The Lord of the Rings: The War of the Rohirrim tells the fate of the House of Helm Hammerhand, King of Rohan. A sudden attack by Wulf, a clever and ruthless Dunlending lord seeking vengeance for the death of his father, forces Helm and his people to make a daring last stand in the ancient stronghold of the Hornburg— a mighty fortress that will later come to be known as Helm’s Deep. Finding herself in an increasingly desperate situation, Héra, the daughter of Helm, must summon the will to lead the resistance against a deadly enemy intent on their total destruction.

The trailer begins with scenes from the live-action LOTR, before transitioning into animation. The familiar fauna of Middle Earth includes giant eagles, Oliphaunts, and maybe the Watcher in the Water. Of course there are battle scenes and even a brief scene featuring the One Ring.

Miranda Otto, who played Eowyn in the original movie trilogy, reprises that role to serve as narrator for the tale. The Lord of the Rings: The War of the Rohirrim also stars the voice acting talents of Brian Cox, Shaun Dooley, Luke Pasqualino, Gaia Wise and Laurence Ubong Williams.

War of the Rohirrim was directed by Kenji Kamiyama from a script by Phoebe Gittins and Arty Papageorgiou. Jackson is one of the film’s executive producers, along with Fran Walsh, Carolyn Blackwood, Toby Emmerich, Richard Brener and Sam Register.

Also in development is a live-action movie, tentatively titled The Hunt for Gollum, directed by Andy Serkis, and season two of Amazon’s Lord of the Rings: The Rings of Power series premieres next week.

Lord of the Rings: The War of the Rohirrim will debut in theaters on December 13th.