The Margaret-Denis partnership was always the key relationship in the Thatcher family. Denis Thatcher was the ultimate Thatcherite: an old-fashioned businessman who, in his sixties, cast aside many of his ingrained instincts to rise to the challenge of acting as consort to the UK’s first woman prime minister.
Though mocked and caricatured in Private Eye, he fulfilled his role in a most intelligent way, serving as the cornerstone of Margaret's life and always placing her interests before his own.
Their daughter Carol summed him up: "He was a shy man, but he had to un-shy himself pretty damn quick. It wasn't a part he ever auditioned for, but he played it brilliantly."
Carol herself, by contrast, may have felt a little neglected, especially by a mother who had a country to run. Ex-MP Jonathan Aitken, an old boyfriend of hers, once related: "Carol and her mother had a tense relationship, with more chill than warmth. Carol admired Margaret from a distance, but did not enjoy being close to her."
The relationship between Margaret and Carol's twin Mark was very different, however: she adored him, despite his persistent weakness for accident-prone escapades. Carol once said ruefully: "He was always more glamorous. In comparison I was one-dimensional and dull."
Lady Thatcher’s adoration for Mark persisted even as he regularly hit the headlines for the wrong reasons, often giving the impression that he lived a high-flying life at around a hundred miles an hour.
Competing in an African car rally with, he admitted, very little preparation, he went missing in the Sahara desert for six days before a search plane eventually located him, fifty kilometres off course.
While he was missing Mrs Thatcher shed a rare public tear, admitting she was "very upset and very distressed." When rescued Mark was however insouciant, affecting to wonder what all the fuss was about.
In another African adventure he became mixed up in an attempt to stage a coup in Equatorial Guinea, which led to a South African court imposing a large fine on him after he entered a plea bargain. Carol said his trial hurt his mother, writing: "I know how terribly it worried her."
The US later refused Mark a visa to enter the country, in what was clearly a blow to the family's pride.
Carol herself came in for criticism when she revealed intimate details of her mother's dementia, writing: "I almost fell off my chair - watching her struggle with her words and her memory, I couldn't believe it. I had always thought of her as ageless, timeless."
But if Mrs Thatcher had occasional problems with her offspring, the most important relationship of her life was clearly that with Denis, who offered unstinting support.
In the earlier years of her career he was able, as a successful executive who made money in the oil business, to offer her financial security. But much more important was the fact that he came close to being the ideal husband for a prime minister.
She once confessed: "I couldn't have done it without Denis. He was a fund of shrewd advice and penetrating comment. And he very sensibly saved these for me rather than the outside world.
"I think the marvellous thing is that he gives me a sense of perspective. If I am upset or think I have done something silly, we talk about it and he makes me see sense."
He in return said with almost touching modesty: "I have been married to one of the greatest women the world has ever produced. All I could produce, small as it may be, was love and loyalty."
The discretion which she appreciated so much was perhaps no great sacrifice for him, since he regarded journalists as "reptiles." He once explained that his father had warned him that "whales don't get killed unless they spout."
Politically his views seemed be at least as far to the right as were hers, though he never gave any public sign of any difference between them.
The Private Eye version of him as a far-right golfer who regarded Labour party people as commies and liked his drink was an exaggeration for humorous effect.
Yet it was by no means an invention: someone once collected the various words he used for a drink. These included an opener, a brightener, a lifter, a tincture, a snifter and a snort.
Carol recalled: "Dad always used to defuse difficult situations with humour. If there was a crisis he'd pour himself a stiff gin and say: `Let's just relax.' He lived on gin and cigarettes and made it to 88."