From 1949 to 1953 Lewis wrote the Narnia stories. As with the science-fiction, these started with a simple idea for a story, but rapidly turned out to be ideal vehicles for stealing Christian ideas "past those watchful dragons", as he put it.
Left: The Kilns, where CS Lewis lived in Headington, Oxford.
They were instantly successful with children, and had the unexpected side effect of providing a new generation of readers for his adult books when they grew up. This continuing process has helped to keep Lewis in general circulation longer than most religious writers.
He then wrote Surprised by Joy, an autobiography that only goes up to his conversion. In 1951, Mrs Moore died. "And so ends the mysterious self-imposed slavery in which Jack has lived for at least 30 years," said his brother Warren.
Lewis had started exchanging letters with Joy Davidman, a New York Jewish Christian writer. She had been left by her husband, with two sons. She and Jack met in 1952 and married in a civil ceremony 1956. At first, this was a sham marriage to save her being repatriated to the United States, but they grew to love each other.
Within six months, though, Joy was diagnosed with cancer. Her boys were the same age as Jack and Warren when cancer took their mother. While she was in hospital they were married "properly" by a priest. She was prayed for, and enjoyed an extraordinary remission. "The doctors predicted a few months of life," Jack said. "A year later the man who took the last x-ray photos was saying, 'These bones are solid as a rock. It's miraculous.'" They took a belated honeymoon and enjoyed a couple of years of married life, but it was not to last. The cancer returned, and Joy died in 1960.
Jack was devastated. He had found the love his life at 60 – a woman he was already married to – and lost her and regained her and lost her finally all within a few years. But he kept a diary of bereavement, which he published anonymously the following year as the gruellingly powerful A Grief Observed.
"What pitiable cant to say, 'She will live forever in my memory!' Live? That is exactly what she won't do. You might as well think like the old Egyptians that you can keep the dead by embalming them. It was H. I loved. As if I wanted to fall in love with my memory of her, an image in my own mind!"
He was not well himself, and died in 1963, on the same day as the writer Aldous Huxley and President JF Kennedy.
Forty years later, his books sell an estimated 1.5 million copies each year, and he is the most widely read religious writer in the English speaking world. The Times Literary Supplement explained his appeal as "a quite unique power of making theology an attractive, exciting and (one might almost say) an uproariously fascinating quest."
He appeals equally to people who are considering Christianity for the first time – because his explanation of it is clear, compelling, unbiased and foundational – and to people who have been Christians all their life, for much the same reasons.
