Confirmation of Dame Muriel's death in a hospital in Florence on Thursday came only yesterday and was announced by the mayor of Civitella della Chiana, the ancient Tuscan town where she had lived for nearly 30 years.
Born Muriel Sarah Camberg in Edinburgh in 1918 to a Jewish Lithuanian father and English mother, Spark's first novel, The Comforters, was not published until 1957.
A talented child - she won the Walter Scott Prize for poetry at 12 - she taught English and trained as a secretary. In 1937 she married Sydney Oswald Spark, a teacher 13 years her senior. They divorced after six years. "It was a big disaster," she later said.
During the war, Muriel Spark worked on propaganda for the Foreign Office. Afterwards she moved to London, and began her literary career. She became editor of the Poetry Review, and went on to write critical studies of Mary Shelley and the Brontë sisters.
Her novels - nearly two dozen, the last of which, The Finishing School, was published in 2004 - are intricately-woven tales of faith and desire, with goodness often gone astray and badness at large. Dame Muriel's finest works include The Ballad of Peckham Rye, The Girls of Slender Means and The Abbess of Crewe, a parody of the Watergate scandal. But it was The Prime of Miss Jean Brodie, published in 1962 and based on her own Edinburgh schooldays, that brought wider fame.
Jean Brodie, played by Maggie Smith in the 1969 film of the novel, a role which won her an Oscar, became emblematic of the clash of passion and intellect with the constraints of humdrum reality and the passing of time.
"All my pupils are the crème de la crème," Miss Brodie memorably says in the book. "Give me a girl at an impressionable age, and she is mine for life."
Muriel Spark converted to Roman Catholicism in 1954. Another convert novelist, Graham Greene, gave her an allowance to help her start writing. In 1968 she moved to Rome and then Tuscany. She was created dame in 1993. "Catholicism," she said, "is the only religion I view as rational. It helps you get rid of all the other problems in your life."
Faith was at the heart of one of the most bizarre family feuds to have broken out in literary circles. In June 1998, Robin Spark, Dame Muriel's son, called police to his Edinburgh flat, provoking a bomb scare. Mr Spark, who retained his Jewish faith, had claimed in public that his mother was also Jewish, not Catholic. The writer's brother, Philip, who died in 2001 in California, denied this. When Robin saw that an unexpected parcel had been sent to him from an address in California, he believed that it was a bomb. It turned out to be a joke gift, but the rift between mother and son had been exposed.
Letters between the twoare held in a vast archive of her personal correspondence in the National Library of Scotland. They are not available for inspection until after the death of Robin Spark.
Additional reporting by Steve Gothard