With exactly one year until its release, Warner Bros. has kicked off the countdown to The Hobbit: An Unexpected Journey with an announcement that confirms the cast of the Peter Jackson's two-part adaptation and provides the first official synopsis:

Both films are set in Middle-earth 60 years before The Lord of the Rings, which Jackson and his filmmaking team brought to the big screen in the blockbuster trilogy that culminated with the Oscar-winning The Lord of the Rings: The Return of the King.

The adventure follows the journey of title character Bilbo Baggins, who is swept into an epic quest to reclaim the lost Dwarf Kingdom of Erebor from the fearsome dragon Smaug. Approached out of the blue by the wizard Gandalf the Grey, Bilbo finds himself joining a company of thirteen dwarves led by the legendary warrior, Thorin Oakenshield. Their journey will take them into the Wild; through treacherous lands swarming with Goblins and Orcs, deadly Wargs and Giant Spiders, Shapeshifters and Sorcerers.

Although their goal lies to the East and the wastelands of the Lonely Mountain first they must escape the goblin tunnels, where Bilbo meets the creature that will change his life forever … Gollum.

Here, alone with Gollum, on the shores of an underground lake, the unassuming Bilbo Baggins not only discovers depths of guile and courage that surprise even him, he also gains possession of Gollum’s “precious” ring that holds unexpected and useful qualities … A simple, gold ring that is tied to the fate of all Middle-earth in ways Bilbo cannot begin to know.

Ian McKellen returns as Gandalf the Grey, the character he played in The Lord of the Rings trilogy, and Martin Freeman in the central role of Bilbo Baggins. Also reprising their roles from The Lord of the Rings movies are: Cate Blanchett as Galadriel; Ian Holm as the elder Bilbo; Christopher Lee as Saruman; Hugo Weaving as Elrond; Elijah Wood as Frodo; Orlando Bloom as Legolas; and Andy Serkis as Gollum.

The ensemble cast also includes (in alphabetical order) Richard Armitage, John Bell, Jed Brophy, Adam Brown, John Callen, Luke Evans, Stephen Fry, Ryan Gage, Mark Hadlow, Peter Hambleton, Barry Humphries, Stephen Hunter, William Kircher, Evangeline Lilly, Sylvester McCoy, Bret McKenzie, Graham McTavish, Mike Mizrahi, James Nesbitt, Dean O’Gorman, Lee Pace, Mikael Persbrandt, Conan Stevens, Ken Stott, Jeffrey Thomas and Aidan Turner.

Curiously, Benedict Cumberbatch, who plays the dragon Smaug and provides the voice of the Necromancer of Dol Guldur, doesn't make the lengthy list.

The screenplays for both The Hobbit: An Unexpected Journey and The Hobbit: There and Back Again are written by Jackson, Fran Walsh, Philippa Boyens and Guillermo del Toro.

The Hobbit: An Unexpected Journey opens on Dec. 14, 2012, and The Hobbit: There and Back Again on Dec. 13, 2013.