Battle of Five Armies
The Battle of Five Armies or Battle of the Five Armies was a long battle started by the goblins of the Misty Mountains. They set out of the mountains with an enormous army of all the goblin tribes, seeking revenge for the death of the Great Goblin. Their force was so great that a joint army of dwarves, elves of northern Mirkwood and Lake-men wasn't enough to stop them. They were saved by the eagles, who flew down from the mountains in great number, and Beorn, who took the shape of a gigantic bear.
Bilbo Baggins was present at this battle at the end of his journey to the Lonely Mountain, although he did not remember much of it, having spent the majority of time lying down unconscious after a blow on his head. -