The Skin Changers: Origin (p3)

Gandalf thought the Beornings might have originated in the Misty Mountains. During the Third Age they guarded the Ford of Carrock from the Orcs and Wargs (in The Lord of The Rings, Gloin complained that their tolls were high) and they also aided the Elves in defending their kingdom in northern Mirkwood. During the War of the Ring, while wearing the One Ring at Amon Hen upon the seat of seeing, Frodo Baggins saw many things from afar, including the land of the Beornings aflame. This hints at an attack by Sauron's forces upon the Beornings, though the outcome of this attack is unknown