No imaginary world has been projected which is at once so multifarious and so true to its own inner laws

CS Lewis

The Hobbit - a sort of prequel to The Lord of the Rings - enjoyed great and instant success when it was published, in 1937.

Some 20 years later, in the wake of the publication of the final part of the trilogy, The Return of the King, WH Auden wrote that the cycle surpassed Milton's Paradise Lost.

However, the American critic Edmund Wilson famously dismissed the work as "juvenile balderdash", and Philip Toynbee wrote in 1961 that Tolkien's works had "passed into a merciful oblivion".

Little did Toynbee suspect that as he was writing his premature obituary, a new generation was adopting the Lord of the Rings as its own.

The trilogy was adopted by the nascent counterculture of the 1960s as an iconic book.

Enthusiasm was such that, in the late 60s, one of London's top rock venues, in Covent Garden, was called Middle Earth, after Tolkien's imaginary world.

Over the years, fan clubs mushroomed, arcane role-playing games based on the Lord of the Rings were developed - and Tolkien's literary stock plummeted.

Even today, a quick trawl through the internet tellingly reveals the existence ofboth a Spanish progressive rock band and a Slovakian "doom rock" group called Galadriel - the name of a Rings character.

Peter Jackson has directed the trilogy

The Lord of the Rings' cult status may have been good for sales, and allowed a surprised Tolkien to retire with far more money than his upbringing in relative poverty could ever have allowed him to expect would one day be his.

But it has obscured The Lord of the Rings' status as an heroic romance to compare with Spenser's Faerie Queen.

Narnia creator CS Lewis wrote of the book: "No imaginary world has been projected which is at once so multifarious and so true to its own inner laws; none so seemingly objective, so relevant to the actual human situation yet so free from allegory."

In the Lord of the Rings, Tolkien the historian distils elements of Norse, Celtic and Teutonic myth into a coherent whole.

Tolkien the linguist devises whole languages for his characters - even if the reader need understand just a few words of these invented tongues.

Tolkien the mythologist then sets about creating layers of what critics of the 70s and 80s would have praised as "intertextuality" - had they not snootily overlooked Tolkien..

An example of this is the way in which the denizens of Middle Earth talk about mysterious events that exist, even for them, in the realm of legend.

Middle Earth is a frightening place

Astonishingly, Tolkien actually fully develops this second fictional level in his book The Silmarillion.

And the Hobbits of The Lord of the Rings are familiar, we are told, with an account of Bilbo Baggins's journey, entitled The Red Book of Westmarch.

This is, of course, the text that we know as The Hobbit.

But as Lewis says, the appeal of the tale lies in more than the mere accumulation of detail.

The characters in The Lord of the Rings operate within a fully developed moral universe, and therefore exist in the realm of literature as well as that of fantasy.

Artist

Countless interpretations have been put on the book - perhaps most commonly, that it is an allegory of World War II.

Many of the 60s generation saw the tale of the One Ring as a fable about nuclear weapons and the need for their destruction.

Tolkien resisted these and all other reductive attempts to make his universe correspond to our own.

Interpretation bounces off the impenetrable surface of The Lord of the Rings.

But the fact that we are still trying to draw out the secrets of The Lord of the Rings testifies eloquently to Tolkien's powers, not just as the architect of a fictional world, but as an artist.