The Brotherhood Without Banners is a group of rebels operating in the Riverlands. They are led by Lord Beric Dondarrion and the red priest Thoros of Myr. The Bortherhood has taken up the cause of the smallfolk in the Riverlands as well as the foreign faith of the Red God, R'hllor. These bandits have been a major thorn in the side of Lord Tywin's forces. These men appear to have been bewitched by the Red Priest and are unlikely to reenter the kings peace. In short, these rebels must be found and destroyed.