Forever associated with Shakespeare's Macbeth, the castle is one of the Highlands' leading tourist attractions, and on Thursday evening the Dowager Countess of Cawdor, Lady Angelika, invited friends and staff to a party celebrating the 30th anniversary of its opening to the public.
It was an idyllic scene, reminiscent of King Duncan's comments in the first act of the Scottish Play: "This castle hath a pleasant seat; the air nimbly and sweetly recommends itself unto our gentle senses."
But - as the ill-fated monarch discovers to his cost - appearances at Cawdor can be deceptive. In the play, Duncan names Macbeth Thane of Cawdor, but is then killed in his sleep by the nobleman and his ambitious wife, Lady Macbeth. Now - six centuries after the events portrayed in Macbeth - Cawdor is once again at the heart of a bitter dynastic rivalry.
Last week, the current Thane of Cawdor, Lady Angelika's stepson, Colin Campbell, found himself on the wrong side of Cawdor's drawbridge.
He was not at the party. Neither were his brother and three sisters, nor any of their immediate family. One of Britain's most distinguished aristocratic families has been frozen out of its ancestral seat.
The snub was the latest chapter in a 13-year feud involving a secret will, a string of court cases and a bitter fight for control of the 14th-century estate. The dispute broke out after the death of the previous thane, Hugh Campbell, in 1992 and will be reignited this week when his eldest daughter, Liza, publishes her memoir of family life at Cawdor.
In Title Deeds, Lady Liza said that her father had "shades of Macbeth", and described him as domineering and embittered alcoholic with a "hefty cocaine habit". Her father was allegedly obsessed with sex and lived on a diet of pink gins, warping his mind so badly he decided to cut his family out of their historical inheritance.
Now Lady Angelika has spoken out in defence of her late husband, accusing her stepdaughter of writing "fiction", possibly just to make money.
"The things she is saying are absolutely untrue. You can't libel the dead, but this is a terrible slur on his memory," she told The Independent on Sunday. "This book is very hurtful - not just for me but for the people of this area. My husband was greatly admired and a lot of people here are deeply hurt by what has been said. Some of the claims made me feel sick," she said.
Lady Liza says that her father's achievements in life amounted to a "list of perfidies". She accuses him of squandering the family fortune, "brutalising his first wife, my mother; discarding friendships like used tissues; indulging in fabulously injudicious sexual adventures [and] destroying his health".
According to Lady Liza, 46, her father was troubled by deep anxieties but terrorised his own family. In an uncanny echo of the ghostly subplot of Macbeth, Hugh Campbell was given to superstition, and at one stage became convinced that his stepmother was using black magic against him. To cover up his own insecurities, he turned to alcohol, which in turn made him "paranoid, belligerent, sexually incontinent and, on occasions, violent", Lady Liza said.
She accuses him of a string of extramarital affairs and describes the night, when she was 16, in which he ordered her to join him in bed - where he promptly passed out in a drunken stupor.
"To this day, I don't know what he intended. Maybe it was just a pre-dawn cuddle, but even that would have fallen far short of being welcome," she wrote.
Yesterday Lady Angelika dismissed the allegations as fantasy. "Quite simply she is making up these ghastly stories about her father. They are quite untrue. What she has written is a novel, a work of fiction ... I can't think why she has done this - to make money, perhaps," she said.
The dowager countess strenuously denied allegations that her late husband was violent or addicted to alcohol and cocaine.
"I was married to this man for 14 years and obviously came to know him well. There was never any shadow of the violence she talks about," she said. "To say that he was a drug addict is crazy. And the alcohol - well, Hugh liked a drink from time to time. But if you applied such standards across all of Britain the entire country would be alcoholics."
Brought up in Rhodesia by parents who fled Czechoslovakia during the Second World War, Lady Angelika married Hugh Campbell in 1979, and remained with him until his death in 1992.
The dispute between Lady Angelika and her stepchildren erupted two weeks later when the contents of his will were revealed. In the words of Lady Liza, it was a "dirty bomb".
Breaking with aristocratic convention, Hugh Campbell did not leave his lands to his eldest son, Colin Campbell, the 26th Thane and 7th Earl of Cawdor. Instead, he left everything to Lady Angelika. His children saw the decision not just as an insult to them but as an affront to centuries of tradition.
"My father had neither earned nor bought Cawdor. These possessions were entrusted to his care. Not only had he shafted his own son in the will rewrite, he had shafted the previous 24 generations. This treasure had survived 600 years of wild Scottish history ... yet it took only one drunken rake to piss it away," wrote Lady Liza.
In a seemingly inexplicable twist, however, the one-page will bound the rival parties together, by making both Lady Angelika and her stepchildren shareholders in the family estates and naming the Earl, Colin, as a shareholder of the company that ran the castle.
The effect of Lord Cawdor's final testament, wrote Lady Liza, was to tie the earl and dowager together "in a way that seemed almost consciously designed for maximum friction".
Tensions grew when Lady Angelika banned her stepson from cultivating GM crops on estate lands, and the situation only grew worse when she accused him of trying to take over the company that manages the castle.
Then, in 2003, came the final straw: while Lady Angelika was on holiday in New York, the young earl took advantage of her absence and moved his family into the castle. It took a court action to evict them, and by then relations had broken down altogether. Three lawsuits arising from the dispute have yet to be resolved.
Lord Cawdor now lives in London with his wife, Lady Isabella, a former fashion editor at British Vogue and Elle. When the couple visit Scotland, they stay in a 12-bedroom "croft" across the moors from Cawdor, where they have entertained guests including the Beckhams and fashion photographer Mario Testino.
But what the children of the 25th Thane of Cawdor want most of all is to regain the castle from their stepmother - who is legally entitled to sell or bequeath the estate to whoever she chooses.
"Angelika could leave it to Robert Mugabe," wrote Liza Campbell.
Lady Angelika has said that she has no intention to sell Cawdor - but this week she hinted at a possible future reconciliation. "I moved in to protect the castle. That is what Hugh wanted. To keep it safe for the future. I will pass on the castle at some point to my stepson - or his eldest child," she said.
Judging by Lady Liza's book, however, neither side seems ready to make peace yet.
Six hundred years after an ambitious thane met three witches on a blasted heath, more "toil and trouble" seems inevitable at Cawdor Castle. For the heirs of Macbeth, the hurly-burly is far from done, and the battle is neither lost nor won.
Extract: 'In his will my father shafted 25 generations'
He died [in June 1992] aged 60. Whatever vulnerability I felt at losing a parent, there was also a sense of deliverance. His angry presence no longer loomed. The power he once wielded had gone. The sense of release within the muddle of grief was short-lived, however, and it vanished altogether when I discovered that there was a grand finale from beyond the grave. None of us had any idea that he had concealed a dirty bomb, timed to detonate only after his death...
My father had neither earned nor bought Cawdor. These possessions were entrusted to his care. Not only had he shafted his own son in the will rewrite, he had shafted the previous 24 generations. This treasure had survived 600 years of wild Scottish history, including a crucial battle fought on its doorstep, yet it took only one drunken rake to piss it away.
Pa's life achievements amounted to a list of perfidies: demolishing Stackpole, the mansion in Wales he inherited as a young man, and selling the family's Welsh estate; brutalising his first wife, my mother; discarding friendships like used tissues; indulging in fabulously injudicious sexual adventures; destroying his health; and then revealing his most wretched act only after his final exit.
From 'Title Deeds' by Liza Campbell, published by Doubleday, £14.99Reuse content