There are some interesting relations between The Hobbit, The Lord of the Rings, and Beowulf.
In Beowulf, the dragon is aroused from centuries of slumber by a thief who stole a cup (see here). In The Hobbit, Smaug the dragon is awakened (after long decades, though not centuries) by Bilbo the Burglar, who stole a cup.
In The Lord of the Rings, we learn that Sauron gave rings to kings of men and dwarves. In Beowulf, we learn that in Anglo-Saxon culture kings were described as “ring givers.” Presumably such rings were given to their nobles as tokens denoting their fealty to the king; if that is so, then we may be safe in concluding that Sauron’s rings were not mere gifts but signs of their recipients’ submission to his dominion.
In Beowulf, there is a character named Éomer; likewise Théoden’s nephew in The Lord of the Rings is Éomer.