Video game developer Turbine and publisher Warner Bros. Interactive Entertainment have announced that they are working on a new expansion for the MMO The Lord of the Rings Online, which will be called Riders of Rohan and is set to launch at some point during the autumn of this year.

The new expansion will allow players, regardless of class or race, to join the fabled Rohirrim in their drive towards war and ride across the plains of Rohan, experiencing events like the split of the Fellowship of the Ring at Amon Hen, the alliance with the Ents of Fangorn and the battles that Éomer, adopted son of Théoden, fights against the Forces of Sauron.

The expansion for The Lord of the Rings Online also adds mounted combat, allowing players to get a war steed that has specific skills and abilities that can be developed in order to turn him into a faithful companion and powerful weapon.

The level cap has also been pushed up to 85, with new skills and abilities added for high level players.

Kate Paiz, who is the executive producer working on The Lord of the Rings Online, stated, “2011 was another banner year for The Lord of the Rings Online with consistent growth for the game, a successful unification of our European and North American services and the success of Rise of Isengard, our best selling expansion to date.”

The executive added, “This is going to be another outstanding year as we celebrate our fifth anniversary and introduce a wealth of new content throughout the year, ending with our arrival in Rohan.

“One of our largest expansions ever, Rohan is expected to be twice the size of the recent Rise of Isengard expansion and includes the most new game systems and technology we've introduced since 2008's Mines of Moria.”

The Lord of the Rings Online now uses a free-to-play model and gamers will be able to access most of the new MMO content without paying for it.