The man behind the wardrobe

Generations of children have entered the magical wardrobe to enjoy The Chronicles of Narnia, and it is these seven books which have ensured the fame of C.S. (Clive Staples) Lewis, who was born in Belfast 100 years ago. They are the ultimate fantasy adventure - colourful, frank, populated by talking animals and full of humour while playing tricks with time-scales, they are also candid morality tales in which the action is invariably presided over by the wise and benign Aslan the Lion, guardian of Narnia and Lewis's inspired, accessible portrayal of a just, exacting but loving Christian God. Whatever about his immense popularity, however, Lewis's lasting literary legacy lies in his scholarly writings, particularly his pioneering critical work on 16th-century English literature. Indeed, as the poet T.S. Eliot, not an admirer of Lewis, remarked to him somewhat left-handedly prior to the publication in 1961 of A Grief Observed: "I consider your preface to Paradise Lost your best book".

Far more significantly, The Allegory of Love (1936), a history of allegorical love literature from the early Middle Ages to the late 16th century, his first major book, not only remains a seminal university text, but stimulated the rediscovery of Edmund Spenser as a great English poet, while Lewis's English Literature in the 16th Century, (volume three of the Oxford History of English literature,) is a superb achievement. For other readers he helped to reinforce - and, more importantly, restore - faith through his plain-speaking religious writings. The Screwtape Letters (1942) in which an elderly devil tutors his junior in the art of temptation, became an international bestseller.

The various voices of Lewis - as inspired critic, as a prodigal returned to Christianity, as popular Christian apologist, as failed poet, as writer of Christian science fiction, as creator of a clever, daringly allegorical adventure saga - who is reported to have once said: "People won't write the books I want, so I have to do it for myself", fail to prepare us for the reality of Lewis the man, who was known throughout his life as Jack and was most memorably described as "a red-faced Belfast butcher".

Lewis took a first in Mods, a First in Greats and the Chancellor's English Essay Prize at Magdalen College, Oxford, but in person rarely conveyed his intellectual sophistication and never achieved the Oxford chair that his inspired style of lecturing and his academic record should have guaranteed him. Possessing a tendency towards earthy humour and laddish behaviour, favouring loud talking, heavy drinking and gauche, enthusiastic pronouncements, he was determined not to fit in and appears to have inspired both love and intense dislike, but seldom indifference. His late marriage to an outspoken American divorced mother of two, Joy Gresham, whom he adored and others detested, further alienated him from his circle. By then his friendship with J.R.R. Tolkien, once the sustaining force of his life, was over. Born in Belfast in 1898, the second son of Albert Lewis, a solicitor, and Flora Hamilton, an honours maths graduate of Queen's University, his first few years were happy. "I fancy happy childhoods are usually forgotten," he was to write in later years. Clearly his early childhood must have been good - he never wrote about it.

His parents were comfortably off; and, in the time-honoured fashion of the middle classes, were swayed as much by snobbery as educational merit in their attitude towards the schooling of their boys, both of whom loved reading.

Content in the company of his brother Warren, little Jack's happiness abruptly changed to sorrow and lasting resentment against his father, when Flora Lewis died in August 1908. By blaming his father for his mother's death, he was also damning God, whom he was to reject for many years. Two weeks after his mother died, nine-year-old Jack was on his way to a small English boarding school, Wynyard House in Hertfordshire. It was an experience he hated and for which he never forgave his father. Warren Lewis had already spent three years there and was not a favourite of the capricious headmaster, a Reverand the Reverend Robert Capron, who considered him lazy.

There, C.S. Lewis discovered corporal punishment and Christianity - albeit in a most brutal guise - which would later become so important to him. His stay at Capron's grim establishment only lasted 18 months, but he never forgot it, describing it as a concentration camp and likening it to Belsen. Escape was secured only when another parent brought a court action for brutality against Capron; the headmaster was ruined and the school closed.

By autumn 1910, Jack was back in Belfast, at Campbell College; by the time he was 13 he had written a remarkable essay on Wagner, the tone of which may be seen in an observation such as: "He has not been, nor ever will be, appreciated by the mass: there are some brains incapable of appreciation of the beautiful except when it is embodied in a sort of lyric prettiness".

Such candour, albeit less priggishly precocious, would in time prove characteristic of his criticism. One of the several pleasures of his academic work is its readability, its directness and exciting overview. Lewis the critic was confident enough to advocate the value of texts over critiques: "It is always better to read Chaucer again than to read a new criticism of him". He shone at prep school and, having completed the papers from his sick bed, won a scholarship to Malvern College. At Malvern, Jack Lewis was suddenly one of many clever boys. His blunt features and lack of beauty, however, helped deflect sexual attention from him. His traumas were to remain rooted in his mother's death. It is no coincidence that Digory in The Magician's Nephew (1955) is preoccupied by his mother's illness. Elsewhere the parents of the evacuated Pevensie children are invariably absent, Shasta in The Horse and His Boy has been raised as an orphan, while the orphaned Prince Caspian separated from his old nurse, the closest relationship he had known, is unexpectedly reunited with her when she is reprieved on her deathbed by Aslan.

By 1914 the safe, middle-class world Lewis knew had changed. At 18, he sat the Oxford scholarship and enjoyed his first term at the university which would dominate his life. But not until he had served at the Western Front - Lewis's membership of the war generation has often been overlooked and yet his use of battle, both as adventure and as allegory, is central to the Narnia stories, while conflict features throughout his religious writings. Although he was later wounded, Lewis admitted to enjoying being a soldier; he liked the atmosphere of cameraderie. Also, during his training, he made friends with a recruit through whom Lewis, ever the motherless boy, was to meet the woman who first replaced his missing mother. Janie Moore, his friend's mother, was 26 years Lewis's senior - and difficult. Initially a maternal figure to him, she was to be his partner for 30 years. The relationship was never formally recognised, yet it certainly helped compromise Lewis's reputation in Oxford. The rest of the damage was done by Lewis himself.

In 1929, Lewis met J.R.R. Tolkien, a medievalist whose imagination delighted him, while his Christianity intimidated him sufficiently to eventually cause Lewis, by then an atheist, not only to regain his faith but to develop into a compelling religious thinker. His crisis of faith underpins his appeal as a religious writer: he understood doubt and belief. It is fascinating that two of Lewis's colleagues and close friends should be early literature scholars: Neville Coghill and Tolkien. The Narnia tales lack the dense detail of Tolkien's Middle Earth. In The Lord of the Rings, Tolkien not only created a world in which the quest for the magic ring provokes dynastic battles; he invented various Elven languages, separate races and complex genealogical histories.

By comparison, the Narnia stories seem less narratively cohesive, slightly haphazard, and are very English in tone - a bit brisk, less overtly heroic than Tolkien's, and full of inconsistencies. Whereas Tolkien was a father who, encouraged by the success of The Hobbit, had embarked on the Lord of the Rings as a way of testing his powers as a storyteller, the childless Lewis made up his stories to entertain real-life children who had been evacuated by the war. Ultimately, perhaps the real objective of the Narnia Chronicles was to recreate the childhood Jack had enjoyed with his brother.

Janie Moore's death in 1951 merely emphasised the natural bachelor C.S. Lewis in fact was. This was utterly upended with the arrival of Joy Gresham into his life. For Lewis, it was romantic love at last, a state to which he had never seemed attracted. Thanks partly to her heroic battle with cancer and early death in 1960, Gresham has been romanticised. She was tough, territorial and verbally abrasive to everyone, with the exception of her besotted husband. Her loss inspired Lewis to write A Grief Observed, an intensely autobiographically based study of loss. "No one ever told me that grief felt so like fear".

The early days of his involvement with Gresham had coincided with his acceptance in 1954 of the newly-created chair of Medieval and Renaissance English at Cambridge. Despite various illnesses, which he endured with often risque good humour, Lewis's impressive critical productivity continued and by the time of his death in 1963 he seemed content, having returned to a life shared almost exclusively with the person he was probably closest to, his brother Warren. In late middle age, they recreated their boyhood world.

His death happened quietly in the afternoon, a few hours after President Kennedy was assassinated in Dallas, Texas - which partly explains why so little fuss was made. Now more than a quarter of a century later, The Chronicles of Narnia remain children's classics, his religious writings continue to sustain and inspire, while scholars and students of Renaissance literature revere him.