British literary critic, scholar and author, known for his classic fantasy stories for children, The Chronicles of Narnia (1950-1956). Its has been said that without Lewis, J.R.R. Tolkien's The Lord of the Rings might never have been written.  After a spiritual search Lewis became one of the most popular spokesmen for Christianity, known as the "Apostle to the Skeptics." Lewis was a fellow of the British Academy but his commercial and popular success somewhat undermined his reputation in the academic world. 

"'When Aslan said you could never go back to Narnia, he meant the Narnia you were thinking of. But that was not the real Narnia. That had a beginning and an end. It was only a shadow or a copy of the real Narnia which has always been there and always will be there: just as our own world, England and all, is only a shadow or copy of something in Aslan's real world. You need not mourn over Narnia, Lucy. All of the old Narnia that mattered, all the dear creatures, have been drawn into the real Narnia through the Door. And of course it is different; as different as a real thing is from a shadow or as waking life is from a dream.'" (in The Last Battle, 1956)

Clive Staples Lewis was born in Belfast, Ireland, the son of Albert James Lewis, a solicitor, and Florence Augusta (née Hamilton), the daughter of a Church of Ireland priest. Lewis was very close to his mother, who taught him to love books and encouraged him to study French and Latin. When he was six, the family moved into a house in the Strandtown area of East Belfast. During his childhood, Lewis created the imaginary country of Bloxen. In the attic of the house he had a "study" where learned and first practiced the craft of writing. Many of these tales were later published in Boxen: The Imaginary World of the Young C. S. Lewis (1985).

Lewis mother, a promising mathematician, died of cancer when he was nine years old. In 1908 he was sent to the Wynyard School in Watford, Hertfordshire, which he later on called "Belsea". Its headmaster was committed to an insane asylum. Lewis once recalled his education at Wynyard as the forced feeding of a "jungle of dates, battles, exports, imports, and the like, forgotten as soon as learned and perfectly useless had they been remembered." After attending Campbell College in the east of Belfast, where he developed a serious respiratory illness, and abandoning his Christian faith at the Malvern College, he was educated privatedly in Great Bookham, Surrey.

Like many other students, he witnessed a number of homosexual relationships, but which he himself rejected. Most of his life, Lewis was unmarried. "I am the product of long corridors, empty sunlit rooms, upstairs indoor silences, attics explored in solitude, distant noises of gurgling cisterns and pipes, and the noise of wind under the tiles. Also of endless books," Lewis wrote in his autobiographical book Surprised by Joy: The Shape of My Early Life (1955). "There were books in the study, books in the drawing-room, books in the cloakroom, books (two deep) in the great bookcase on the landing, books in a bedroom, books piled as high as my shoulder in the cistern attic, books of all kinds reflecting every transient stage of my parents' interests, books readable and unreadable, books suitable for a child and books most empathically not. Nothing was forbidden me. In the seemingly endless rainy afternoons I took volume after volume from the shelves..." Lewis's early favorites were Edith Nesbit's books, among them The Story of the Amulet (1906), which mixed fantasy with reality, and the uncut edition of Gulliver's Travels. Later he read the Norse myths and sagas, and such historical books as Henryk Sienkiewicz's Quo Vadis and Lew Wallace's Ben Hur. He also found The Odyssey, Voltaire, Milton and Spenser. Lewis's private tutor, W.T. Kirkpatrick, taught him to read Greek for pleasure.

In 1916, Lewis won a scholarship to University College, Oxfird. While in Keble Kollege, where Lewis had joined a cadet battalion, Lewis met Mrs Janie King Moore, a much older woman – she was 45 at that time and had separated from her husband. Mrs Moore was the mother of Edward Francis Courtenay ("Paddy") Moore, with whom Lewis shared rooms and who was killed in combat.

From 1917 to 1919 Lewis served in the Somerset Light Infantry. He experienced on the battlefields of France the horrors of trench warfare, but in his later writings he did not speak much of the Great War. To calm his nerves under shell fire, he read voraciously and wrote poems. In February 1918, he was hospitalized for "trench fever," a disease spread by body lice.

During the Battle of Arras, Lewis was wounded in the back by a German shell. While convalescing, he met again Mrs Moore, who followed him to Oxford with her daughter Maureen. However, Lewis concealed this from his father. In 1930 he moved into "The Kilns," a house on the outskirts of Oxford. A number of children found shelter and safety at the Kilns during WWII. Mrs Moore died in January 1951, at the age of seventynine. In her later years she suffered from dementia and was moved into a nursing home.

Lewis graduated in 1923 from University College, Oxford, where became a fellow and tutor in English literature at Magdalen College, Oxford, serving in that post nearly thirty years. For short periods he served as a lecturer at the University of Wales, the University of Durham, and other places. Lewis disliked traveling but he spent hours each week responding to letters he received from all over the world. His lectures were crowded – he had a phenomenal memory, and he could speak spontaneously about Greek and Latin texts without notes. Between 1954 and 1963 he was professor of Medieval and Renaissance English at Cambridge, remaining there until his death.

With J.R.R. Tolkien and Charles Williams, Lewis formed a literary group called 'The Inklings', which took shape in the 1930s. Their Tuesday lunchtime sessions at the Bird and Baby pub became a well known part of Oxford social life. Tolkien himself was a Roman Catholic and he was never quite happy with Lewis's embracing of the Anglican Church. Williams died in 1945 and the meetings faded away in 1949. Acknowledging Tolkien's literary achievement with his The Lord of the Rings trilogy Lewis even proposed him for the 1961 Nobel Prize for Literature. Among other members of the club were Christopher Tolkien and Owen Barfield. Lewis preferred the company of men. He considered that women's minds were intrinsically inferior to men's. A visitor at the Socratic Society of Oxford portrayed Lewis as "ruddy of complexion, radiating health, of substantial girth all over, and his eyes sparkled with mirth."

As Surprised by Joy demonstrates, the watershed in Lewis's life was his conversion from atheism to Christianity. He had began to lose his faith at the age of 13, partly due to his deep-rooted pessimism, and partly due to pantheistic experiences and interest in Wagner's music. After reading such writers as Chesterfield, Bergson, George MacDonald, and George Herbert, and abandoning his youthful snobbery, he became a deist in 1929, and later he was associated with such neo-Christians as T.S. Eliot, W.H. Auden, Dorothy L. Sayers, and J.R.R. Tolkien; some other teachers at Oxford also influenced him.

In the 1930s Lewis started to publish popular religious books, including The Pilgrim's Regress (1933), a thinly disguised allegory of his own conversion, which he wrote in Ireland in two weeks. Lewis's conversion and his reputation as a prominent Christian writer and radio personality strained his relationship with Mrs Moore, who declared herself an atheist later in life. The Screwtape Letters (1942) was a correspondence from a senior devil to his nephew concerning the latter's task of winning a young man to damnation. The Problem of Pain (1940) asked, "If God is good and all-powerful, why does he allow his creatures to suffer pain?" Lewis suggested that much of the suffering in God's world can be traced to the evil choices people make. In his own life, Lewis followed Christian principles. He gave away two-thirds of his income, sat at the bedside of the sick, and personally served the poor.

Lewis's literary criticism opposed classical, traditional, and purely literary values in favour of the biographical, psychological, and impressionistic. However, it took a long period before he began to appreciate modern poetry. Lewis was the chief spokesman for the view that a good reader receives the text, it affects one's senses, but the bad reader "uses" it – the text relieves one's life but does not add to it. Among Lewis's most substantial books is English Literature in the Sixteenth Century (1954). As an essayist Lewis did not avoid controversial issues. In 'The Humanitarian Theory of Punishment' he questioned the idea that to seek to "cure" a criminal is nobler than to rely on punishment. Islam he described as "a Christian heresy."

In Out of Silent Planet (1938) Lewis put his Christian beliefs in the setting of a science fiction story. The book started Lewis's Ransom trilogy, where the achievements of science are in alliance with those of demonic evil. In the first part Ransom is kidnapped by an amoral Wellsian scientist, Weston, and taken to Mars. The series continued in Perelandra (1943), in which an angel carries Ransom to Venus. In That Hideous Strenght (1945) Ransom is back on Earth, and calls Merlin to fight against an unpleasant scientific organization, the N.I.C.E., the National Institute of Co-ordinated Experiments.

The Chronicles of Narnia has turned out to be the most lasting of Lewis's novels. "I wrote the books I should have liked to read," Lewis said. "That's always been my reason for writing." The Chronicles tell the story of a group of children, who come into contact with the mysterious other world of Narnia, where the lion Aslan is the prototype of Christ. "I don't know where the Lion came from or why He came," Lewis explained later. "But once He was there He pulled the whole story together." The portal to Narnia, a kind of medieval vision of Paradise, is a wardrobe through which the four sibling children, Peter, Susan, Edmund, and Lucy enter a secondary world. In the first story the bad Witch is destroyed in a battle. In the sequels the children travel in Narnia and meet sea monsters, dragons, mermaids, wizards and other creatures. Turbaned, dark-skinned people called Calormenes, who worship a demon named Tash, also cause trouble – Lewis's view of Muslims couldn't be more explicit. The final books deal with Narnia's beginning and end. In the last Armageddon story, with its death-and-resurrection theme, the struggle is between young King Tirian and the forces of evil, as represented by Shift the Ape and Puzzle the donkey. The harmony of Narnia is destroyed and Father Time puts out the sun. Jill and Eustache appear from a railway train to help young Tirian, "last of the Kings of Narnia." Aslan reveals the truth: the children were killed in a railway accident. "Your father and mother and all of you are – as you used to call it in the Shadowlands – dead. The term is over: the holidays have begun. The dream is ended; this is the morning." Lewis ends the book telling that they lived happily ever after – it was for them only the beginning of the real story.

Lewis was briefly married to Helen Joy Davidman, a Jewish American poet, a former Communist, who had two children. They met in 1952, but their correspondence had started before it. Lewis's years at Cambridge were happy – Joy Davidman was always good-humoured and shared his delight in argument for argument's sake. She died of cancer in 1960. Lewis keep the marriage secret from Tolkien, which caused tension in their friendship. Lewis's notes from this period was published under the title A Grief Observed (1961) The relationship was the subject of the film Shadowlands (1994), directed by William Nicholson and starring Debra Winger and Anthony Hopkins. Shadowlands was based on Nicholson's television script from 1985 and a successful stage play. Lewis died of osteoporosis on November 22, 1963, the day when President Kennedy was assassinated in Dallas, Texas.

Though Lewis returned to Ireland for his annual vacation almost every year of his life and his language echoed his origins, his stature in the Irish literary pantheon has remained marginal. In 1988 Kathryn Lindskoog published a study (The C.S. Lewis Hoax) in which she questioned the authenticity of a number of Lewis's works published from 1966 to 1991, among them The Dark Tower (1977). Lindskoog continued the debate in Light in the Shadowlands (2001), claiming that the author's posthumous books are at least partly spurious.

For further reading: C.S. Lewis: A Biography by Roger Lancelyn Green and Walter Hooper (1974); The Inklings by Humphrey Carpenter (1978); Shadowlands: The Story of C.S. Lewis and Joy Davidman, by Brian Sibley (1985); C.S. Lewis and the Search for Rational Religion by J. Beverluis (1985); Clive Staples Lewis by W. Griffin (1986); The C.S. Lewis Hoax by Kathryn Lindskoog (1988); C.S. Lewis: A Biography by A.N. Wilson (1990); The Fiction of C.S. Lewis by K. Filmer (1993); The Chronicle of Narnia by C.N. Manlove (1993); The Man Who Created Narnia by M. Coren (1996); C.S. Lewis: Christian and Storyteller by B. Gromley (1998); Sleuthing C.S. Lewis: More Light in the Shadowlands by Kathryn Lindskoog (2001); C.S. Lewis, My Godfather: Letters, Photos, and Recollections by Laurence Harwood (2007); Companionship in Grief: Love and Loss in the Memoirs of C.S. Lewis, John Bayley, Donald Hall, Joan Didion, and Calvin Trillin by Jeffrey Berman (2010); C. S. Lewis - A Life: Eccentric Genius, Reluctant Prophet by Alister McGrath (2013) - See other creators of imaginary lands: Lewis Carroll (Wonderland), J.M. Barrie (Never Never Land), L. Frank Baum (Oz), J.R.R. Tolkien (Middle-earth), Tove Jansson (The Moomin Valley)

Selected bibliography:

• Spirits in Bondage: A Cycle on Poems, 1919 (verse as by Clive Hamilton)
• Dymer, 1926 (verse as by Clive Hamilton)
• The Pilgrim's Regress, 1933
• The Allegory of Love: A Study in Medieval Tradition, 1936
• Out of the Silent Planet, 1938 (Ransom Trilogy)
  - Äänetön planeetta (suom. Matti Kannosto, 1983)
• Rehabilitations and Other Essays, 1939
• The Personal Heresy, 1939 (with E.M.W.Tillyard)
• The Problem of Pain, 1940
  - Kärsimyksen ongelma (suom. Maritta Pesonen, 1963)
• A Preface to Paradise Lost, 1942
• The Screwtape Letters, 1942 (reprinted with some alterations in 1955)
  - Paholaisen kirjeopisto (suom. Tyyni Tuulio, 1980; Taneli Junttila, 2007)
• The Weight of Glory, 1942
• Broadcast Talks, 1942
• Hamlet: The Prince or the Poem?, 1942  (Annual Shakespeare Lecture of the British Academy)
  
• Christian Behaviour, 1943
• Perelandra, 1943 (Ransom Trilogy)
  - Matka Venukseen (suom. Matti Kannosto, 1984)
• The Abolition of Man, 1943
• Beyond Personality, 1944
• That Hideous Strength, 1945 (Ransom Trilogy)
  - Piinattu planeetta (suom. Matti Kannosto, 1985)
• The Great Divorce: A Dream, 1945
  - Suuri avioero (suom. Kari Krohn, 1970)
• The Chronicles of Narnia: The Lion, the Witch and the Wardrobe, 1950 (film 2005, dir. by Andrew Adamson, starring Georgie Henley, Skandar Keynes, William Moseley, Anna Popplewell, Tilda Swanson); Prince Caspian, 1951 (film 2008, dir. by Andrew Adamson, starring Ben Barnes, William Moseley, Anna Popplewell, Skandar Keynes, Georgie Henley); The Voyage of the Dawn Treader, 1952; The Silver Chair, 1953;The Horse and His Boy, 1954; The Magician's Nephew, 1955; The Last Battle, 1956
  - Velho ja leijona (suom. Kyllikki Hämäläinen, 1960); Prinssi Kaspian: paluu Narniaan (suom. Kyllikki Hämäläinen, 1975); Kaspianin matka maailman ääriin (suom. Kyllikki Hämäläinen, 1976); Hopeinen tuoli (suom. Kaarina Helakisa, 1976); Hevonen ja poika (suom. Kaarina Helakisa, 1977); Taikurin sisarenpoika (suom. Kyllikki Hämäläinen, 1959); Narnian viimeinen taistelu (suom. Kaarina Helakisa, 1979)
• George MacDonald: An Anthology, 1946 (ed.)
• Man or Rabbit?, 1946
  
• Miracles: A Preliminary Study, 1947
• Essays Presented to Charles Williams, 1947 (ed.)
  
• Arthurian Torso, 1948 (ed.)
• Vivisection, 1948
• Transpositions and Other Addresses, 1949
• The Literary Impact of the Authorized Version, 1950 (the Ethel M. Wood lecture delivered before the University of London, etc.) 
• Mere Christianity, 1952
  - Ehyt elämä (suom. Ruth Wathén, 1962) / Tätä on kristinusko (suom. Marja Liljeqvist, 1978)
• Hero and Leander, 1952
• English Literature in the Sixteenth Century; Excluding Drama 1954
• Surprised by Joy: The Shape of My Early Life, 1955
  - Ilon yllättämä (suom. Ritva Miettinen, 1986)
• Till We Have Faces, 1957
•  Reflections on the Psalms, 1958
  - Mietteitä psalmeista (suom. Marja Liljeqvist, 1982)
• Shall We Lose God in Outer Space? 1959
• The Four Loves, 1960
  - Neljä rakkautta (suom. Taisto Nieminen, 1982)
• The World's Last Night and Other Essays, 1960
• Studies in Words, 1960 (rev. 1967)
• A Grief Observed, 1961 (as N.W. Clerk)
  - Muistiinpanoja surun ajalta (suom. Anna-Mari Kaskinen, 1984)
• An Experiment in Criticism, 1961
• The Screwtape Leters, and Screwtape Proposes a Toast, 1961
  
• They Asked for a Paper: Papers and Addresses, 1962
• The Discarded Image: An Introduction to Medieval and Renaissance Literature, 1964
• Poems, 1964 (ed. Walter Hooper)
• Letters to Malcolm: Chiefly on Prayer, 1964
• Of the Other Worlds: Essays and Stories, 1966 (ed. Walter Hooper)
• Studies in Medieval and Renaissance Literature, 1966 (ed. Walter Hooper)
• Letters to an American Lady, 1967 (ed. by Clyde S. Kilby)
  
• Christian Reflections, 1967 (ed. Walter Hooper)
  - Entisen ateistin kristillisiä esseitä (suom. Olavi Aula, 1968)
• Mark vs. Tristram: Correspondence between Lewis and O. Barfield, 1967 (ed. Walter Hooper)
• Spenser's Images of Life, 1967 (ed. by Alasdair Fowler)
  
• A Mind Awake: An Anthology of C.S. Lewis, 1968 (ed. Clyde Kilby)
• Selected Literary Essays, 1969 (ed. Walter Hooper)
• Narrative Poems, 1969 (ed. Walter Hooper)
  
• God in the Dock: Essays on Theology and Ethics, 1970
• Undeceptions. Essays on Theology and Ethics, 1971 (ed. Walter Hooper)
• The Humanitarian Theory of Punishment, 1972
• Fern-Seed and Elephats and Other Essays on Christianity, 1975  (ed. Walter Hooper)
• The Dark Tower and Other Stories, 1977 (ed. Walter Hooper)
• They Stand Together: The Letters of C.S. Lewis to Arthur Greeves, 1979 (ed. Walter Hooper)
  
• C.S. Lewis at the Breakfast Table, 1979 (edited by James T. Como) 
• The Visionary Christian: 131 Readings C.S. Lewis, 1981
• Of This and Other Worlds, 1982 (ed. Walter Hooper)
• On Stories; And Other Essays on Literature, 1982  (ed. Walter Hooper)
• The Cretaceous Perambulator, 1983 (ed. Walter Hooper)
• The Business Of Heaven, 1984 (ed. Walter Hooper)
• Letters to Children, 1985 (eds. L.W. Dorsett, M. Lamp Mead
• Boxen: The Imaginary World of the Young C.S. Lewis, 1985  (ed. Walter Hooper)
• Present Concerns, 1986 (ed. Walter Hooper)
• Timeless at Heart, 1987 (ed. Walter Hooper)
• The Essential C.S. Lewis, 1988 (ed. Lyle W. Dorsett)
  
• Letters: C.S. Lewis and D.G. Calabria, 1989 (ed. M. Moynihan)
• All My Road Before Me: The Diary of C. S. Lewis 1922–27, 1991 (edited by Walter Hooper, foreword by Owen Barfield)
• The Collected Poems of C. S. Lewis, 1994 (ed. Walter Hooper)
  
• Essay Collection & Other Short Pieces, 2002 (ed. Lesley Walmsley)
  
• Collected Letters, 2004-2006 (3 vols., ed. Walter Hooper)
  
• The C.S. Lewis Bible, 2010 (ed. Michael Maudlin)
• C.S. Lewis's Lost Aeneid: Arms and the Exile, 2011 (ed. A. T. Reyes)