War of the Ring
As stated by Glóin in "The Fellowship of the Ring", the Beornings "keep open the High Pass and the Ford of Carrock." In the events leading up to the War of the Ring, the Beornings assist Aragorn, who was taking Gollum to Mirkwood, to cross the Anduin. They also aid the Elves of Mirkwood in their battles against Sauron's forces. While wearing the One Ring at Amon Hen during the War of the Ring, Frodo Baggins perceived many things from afar, including the land of the Beornings aflame, suggesting an attack by Sauron's forces.