Warhammer Online: Age of Reckoning.
(http://warhammeronline.com/)

"War is everywhere in Warhammer® Online: Age of Reckoning™ (WAR), the new fantasy MMORPG from Mythic Entertainment, the creators of Dark Age of Camelot™. WAR features next generation Realm vs. Realm™ gameplay that will immerse you in a world of perpetual conflict for years to come.

Experience the glory of Realm vs. Realm! Declare your allegiance and join hundreds of thousands of mighty heroes on the battlefields of Warhammer Online: Age of Reckoning to experience the epic nature of war. Enter a grim fantasy world where the armies of Order (Dwarfs, High Elves, and Empire) and Destruction (Greenskins, Dark Elves, and Chaos) collide to determine the fate of nations. Invade enemy lands, besiege imposing fortresses, and sack sprawling capital cities for the glory of your Realm. Wield devastating magic and deadly weapons, battle monstrous creatures, and join your brothers-in-arms in epic Public Quests™. Climb the Bastion Stair, carry your Guild Banner into battle, and unlock the secrets of the Tome of Knowledge as you travel the world. Sharpen your blade and prepare to unleash your inner mutation-the Age of Reckoning has begun and WAR IS EVERYWHERE!"
Credit to Warhammer Online website.