The impression of depth in The Lord of the Rings is an aesthetic effect deliberately sought by its author, J. R. R. Tolkien. It was intended to give the reader the feeling that the work had "deep roots in the past", and hence that it was attractively authentic.
The effect was constructed on at least four factors, namely the enormous scale of The Lord of the Rings and the amount of background detail, including maps and genealogies; the apparently casual and incomplete mentions of this background; multiple inconsistent accounts, as in real history; and writing different texts in varying styles.
Scholars have noted some of Tolkien's medieval antecedents in the effect, such as Beowulf and Sir Gawain and the Green Knight. Fantasy authors such as Ursula K. Le Guin and J. K. Rowling have to an extent followed Tolkien in using the technique.