As The Lord of the Rings' Fellowship assembled and began traveling toward Mordor, Sauron was preparing for war. The Dark Lord didn't expect subterfuge. He expected Gandalf and company to take the One Ring to Gondor so that Aragorn could wield it against him. So, he mustered all of his armies and got ready to fight. Of course, Sauron was wrong because Frodo took the Ring and secretly snuck across the Anduin River. But even with his miscalculation, war was afoot in Middle-earth.
Sauron never wanted to participate in the fight, but his armies were spread out and poised to take over Middle-earth. It was the culmination of the Third Age, pitting Sauron against the free peoples of the world. And regardless of Frodo's efforts, multiple leaders -- including Galadriel, Celeborn, Dáin II Ironfoot and King Brand -- had to take up arms to defend their people. As the impending doom approached, everyone was ready to fight, but there was someone missing. Where was Beorn during the War of the Ring, and why didn't he fight against Sauron?
Beorn Was a Fearsome, Shape-Shifting Bear
Beorn was one of the most interesting figures in The Lord of the Rings. He was a large man and a great warrior, but more importantly, Beorn was a skin-changer. Somehow, he could transform into a massive bear. In The Hobbit book, he ruled over the Beornings, who were all skin-changers. But in the movie version, Azog the Defiler had come down from the mountains and persecuted his kind, leaving Beorn as the only survivor.
Although he wasn't overly fond of Dwarves, Beorn allowed Gandalf, Bilbo and the rest of Thorin's company to stay with him on their quest to Erebor. After that, he lent them ponies for the journey to Mirkwood. But that wasn't the last appearance he made. Beorn showed up just in time at the Battle of the Five Armies and made a huge difference in the fight. In the book version, he personally killed Bolg and his legendary bodyguards, and he rescued Thorin's body from the fray. In the movie, he had less of a direct impact, but he still helped win the day.
Beorn Was Already Dead in The Lord of the Rings
Because Beorn was so important in The Hobbit, it's reasonable to question why he didn't make an appearance in the LOTR trilogy. He didn't like Sauron and would have fought against him, but Beorn was dead before the War of the Ring began. Men like Aragorn, who had Númenórean blood, lived extra-long lives, but Beorn was not of Númenórean descent. So, combine Beorn's age in The Hobbit with the 60 years between The Hobbit and the LOTR trilogy -- not to mention the 17-year time jump in FOTR -- and Beorn had been dead for a while.
Beorn never had a chance to appear in the LOTR trilogy, but his son did. When Beorn died, his son Grimbeorn the Old became lord of the Beornings. In FOTR, Gloin mentioned that Grimbeorn charged a high tole for keeping the High Pass and the Ford of Carrock clear of Orcs and Wolves. In The Lord of the Rings Online, Grimbeorn had to entertain Elrond and his household while they were journeying to Minas Tirith for Arwen's wedding. Like his father, he wasn't overly fond of company, so that wasn’t the most enjoyable experience. But he was a good Man and definitely against Sauron and his evils.