She liked to run with a well-heeled artistic crowd, imagining it to be “bohemian” – though the true bohemia of the talented yet impoverished was unknown to her. Nor could anyone carry on eating after Margaret had stopped. She exploited to the full the royal protocol of guests not being allowed to sit down to dinner, or leave, or even go to bed, until the royal party had done so themselves. As he puts it, she conscientiously set people “at their unease”. She was, according to Brown, “the world’s most difficult guest” from her mid-20s onwards: bossy, demanding, volatile and petty. This was a cheap way of establishing precedence: cheap in both senses.

Oh no, you’re not that close.” Keith Waterhouse, at a reception, alarmed at watching the ash get longer and longer on the royal fag, began to reach for an ashtray but she found a quicker solution by tapping the ash off into Waterhouse’s passing palm. She snatched it from his hand and passed it swiftly to a neighbouring ballet dancer with the rebuke, “You don’t light my cigarette, dear. She once invited Derek Jacobi to dinner at a Covent Garden restaurant he thought they were getting on pretty well, until she took out a cigarette and he politely raised a lighter in her direction. There are other examples of such petty nicotine power play in Craig Brown’s roistering quasi-biography of the chain-smoking princess. Then she contentedly lit her own cigarette. Sean Connery had given it to her, she told him. “Isn’t this fun?” she remarked, showing him a gold item with “007” engraved on it. She took another cigarette from her bag, swiftly followed by her own lighter. A while later, he found himself sitting on a sofa with the princess. Obligingly, he turned to a passing guest, borrowed a lighter and indulged her fastidiousness. But she stopped him: no, she said, she couldn’t abide book matches.

He dug out some matches and prepared to fire up the princess. She was, however, famously royal, so when she reached into her bag, extracted a cigarette and pointed it towards Strand, he knew his (republican) duty. The princess was not tall – indeed, she was christened “the Royal Dwarf” in 1951 – was sharp of speech and not jam-packed with noblesse oblige. Strand was extremely tall, very deliberate of speech and gait, well mannered and craggily handsome – the overall effect was of Clint Eastwood’s bookish, better-looking older brother. This happened at a New York cocktail party, and must have been an incongruous encounter. T he only friend I have had who met Princess Margaret was the US poet Mark Strand.

Ma am darling craig brown