MY immediate thought on reading the reports of the death of Robin Spark – who died earlier this month in Edinburgh aged 78 – was relief that his mother, Muriel, was not around to read them. Had she been, I imagine her reaction would have been a combination of disbelief, anger and frustration. For according to the obituarists, she had “abandoned” Robin, or “Sonny” as she affectionately nicknamed him, dispatching him to a boarding school while she pursued a career as a writer in London.

Thereafter, we were led to believe, she and he had little to do with one another. While her son was brought up by her mother and father in the Bruntsfield tenement where she had lived for her first eighteen years, Muriel was selfishly and single-mindedly going her own way. The insinuation was clear. Here was a woman who was a mother in name only. Moreover, she was callous, unfeeling and irresponsible. Art, it seems, came first, all else a distant second. A child was merely an inconvenient impediment to her achieving greatness.

At this point I should perhaps declare that in respect of Muriel Spark I am not an objective commentator. For the last sixteen years of her long and wonderful life – she died in 2006, aged 88 – I saw her as often as time would allow. With her dear friend and helpmate, Penelope Jardine, she lived in a fourteenth century rectory deep in the Tuscan countryside where she could work without fear of interruption. Come evening, however, she would put down her pen – she never adopted new technology – and would sit at the table in the cramped kitchen and enjoy a glass of the local wine.

Often on these occasions, when Robin’s name came up in conversation, her brow would furrow and a look of pain would come into her rheumy eyes. Usually, this was because he had done something to upset her. For example, a cheque she had sent him had been returned uncashed. Or he had spoken to a newspaper, suggesting that by insisting that she was a Catholic – the philosophical bedrock of her work – she was an anti-semite. “He really is the limit,” she would say, and that would be that.

By then Muriel had come regretfully to the conclusion that she and Robin would never see eye to eye. That he nursed a grievance against her was surely the case. But on what was this based? He was born in Africa in 1938 when Muriel was 20. A year earlier, she had impetuously married his father, Sidney Oswald Spark, who was thirteen years her senior, and who neglected to tell her had been seeing a psychiatrist before they wed. Not without reason did Muriel nickname him SOS.

That he was mentally unstable, however, soon became apparent. He was also violent and beat Muriel. The marriage was over almost as soon as it had begun. But what was Muriel to do now? War had broken out and it was impossible to find a berth on a boat that would take her home. Incredibly, custody of Robin was given to his unstable father which meant that Muriel could not take him with her even if she could find an escape route. She knew she wanted to be a writer but she also knew that to do so she had little chance of achieving that in her present situation; London was her only hope.

In February 1944 she was able at last to leave Rhodesia. Conditions were primitive and the journey fraught with hazard. But, as Martin Stannard, Muriel’s biographer noted, danger was the last thing on her mind. She was like a unjustly-convicted prisoner released from a life sentence.

It was also always her intention to be reunited with Robin but the influence of his father grew and poisoned him against his mother. In later years, while she struggled to earn enough to keep herself as well as contribute to Robin’s and her parents’ upkeep, he would cite her non-appearance on important personal occasions as examples of her neglect. One such was his bar mitzvah, a consequence of his embrace of Judaism. Muriel paid for this out of the prize money she won from a short story competition but she did not attend it, not because she didn’t want to, but because she knew that her former husband would be there and might cause a scene.

There were countless other instances of her generosity to Robin and SOS that were forgotten in the ongoing and enervating feud. She contributed to the cost of the latter’s care in East Lothian in his declining years and she handed over the family home to Robin. That she left him out of her will – another of the brickbats thrown at her – is hardly surprising given his avowed refusal to accept any offer of help. Communication between them was difficult, barbed, then non-existent.

It was one of the principal reasons why her visits to Scotland and Edinburgh in particular were so infrequent. This grieved her for she loved the place that had formed her. Its literature was bred in her bones and her sentences ring with the cadences of her forebears: Stevenson, Scott, the Border balladeers. In 2004, I persuaded her to attend the Edinburgh International Book Festival. Even then, though, she felt unnerved by the presence of her son and and worried he might prove disruptive. So she preferred to stay in Melrose before her appearance in Charlotte Square. Few who were there that day will forget it. As she read in her inextinguishable Morningside brogue from The Prime of Miss Jean Brodie, by some distance the greatest Scottish novel of the twentieth century, you could sense that at last Muriel Spark felt happy to be home.