Bust-up at Brideshead: After 58 years in iconic Castle Howard, owner forced out with his chatelaine in stunning coup... by his own brotherÂ Simon Howard is set to leave 10,000-acre Castle Howard with wife Rebecca Friends say he was forced to step down by his elder brother Nicholas Couple and their 12-year-old twins are said to be 'devastated' and 'in shock' At the time Simon was being treated for throat cancer but he is now clear Nicholas and his wife Victoria Barnsley have said they intend to move inÂ Yorkshire estate was the setting for the TV series Brideshead Revisited By Jonathan Petre and Nick Craven for The Mail on Sunday It is perhaps the greatest of stately homes, the sprawling Yorkshire estate that was setting for the television series adaptation of Brideshead Revisited. And now the breathtaking spectacle of Castle Howard is again the setting for the turbulent drama of an ancient aristocratic family. The Mail on Sunday has learned that Simon Howard, who has run the 18th Century home for 30 years and lived in it his whole life, is set to leave the 10,000-acre estate along with his wife Rebecca â€" and Simon's elder brother Nicholas and his wife Victoria Barnsley have indicated to Simon that they intend to move in. Simon Howard and his wife Rebecca have been forced to leave 10,000-acre Castle Howard by his brotherÂ Friends of Simon say he was approached by Nicholas and Victoria in September and asked to step down as chairman of the board that runs Castle Howard, or face being outvoted by the directors of the private company. At the time Simon, 58, was being treated for throat cancer, although he has recently been told he is clear of the disease. It is understood that staff at the North Yorkshire ancestral seat will be told tomorrow of the changes, and Simon and Rebecca are said to be 'in shock' and 'devastated'. A friend of the couple said: 'It is beyond belief. Simon was a wreck of a man when he heard. His heart is ripped apart. The house is his whole life. Nicholas Howard and his wife Victoria Barnsley have said they intend to move in to the sprawling estateÂ Another friend close to the family expressed her outrage over the move, especially after the success that Simon has found in running the estate, which attracts a quarter of a million visitors a year. The friend said: 'Simon has run a very tight ship. The house has been his lifeblood. Rebecca has been an incredible chatelaine. She has run the place amazingly inside and out. She adores the place because she has always been into history. The timing of this has been deeply upsetting for the family. Castle Howard, which was designed by Sir John Vanbrugh and built between 1699 and 1712, has been home to ten generations of the Howard family. Spreading out over 145 rooms, the house is considered one of Vanbrugh's greatest achievements. Its magnificent art collection includes ancient sculptures, Old Masters and works by Joshua Reynolds and Thomas Gainsborough. The house and estate is owned by Castle Howard Estates Ltd, of which Simon, who is chairman and managing director, and his elder brother Nicholas, 62, are each 50 per cent shareholders. In February, Victoria, 60, who was the chief executive officer of London publishing giant Harper Collins until she stepped down in August 2013, also joined the Castle Howard board, but Rebecca has never been elevated to such a position of control, despite helping to run the household. The iconic estate was the setting for the TV series Brideshead Revisited starring (l-r) Anthony Andrews, Diana Quick and Jeremy Irons Exactly what has happened behind the scenes to bring about the switch at Castle Howard was not clear last night, although friends said Rebecca, 47, herself a scion of the Sieff family who founded Marks & Spencer, feels badly treated. One said: 'Rebecca felt that if there was a position on the board of directors that naturally, as Simon's wife and the chatelaine of the house, she would be accepted immediately on to the board. However, this was rejected. I don't know the ins and outs of this but I think Simon felt very pushed into a corner. 'I know that Rebecca was deeply hurt and upset and couldn't really understand what was going on.' According to another friend, the addition of Victoria to the board, whose directors include Nicholas's 28-year-old son George, meant that Simon feared he could be voted out because of his health issues, and he felt he had little option but to give up the running of the estate, although he is to remain a director of the company. Castle Howard, which was designed by Sir John Vanbrugh and built between 1699 and 1712, has been home to ten generations of the Howard family Spreading out over 145 rooms, the house is considered one of Vanbrugh's greatest achievements There is strong speculation that he, Rebecca and their 12-year-old twins, Merlin and Octavia, who are educated locally, will move out of the house, where they occupy one of the wings. One friend said that Simon and Rebecca had been told that one likely consequence of the 'putsch' is that Nicholas and Victoria will move into Castle Howard. Simon, the former High Sheriff of North Yorkshire, has been waging a battle with throat cancer for much of this year, but a medical scan last week found he was free of the disease. In August, he said: 'A lump was removed from my throat and it was found to have cancerous squamous cells. It was a bit of a shock at the time, but it was removed successfully and I have just completed a precautionary seven-week course of radiation therapy. As things stand, I have been very lucky and I am in the clear. According to a family friend, the latest development will cast a shadow over the festive preparations at the estate, where an elegant row of illuminated Christmas trees already line the driveway. 'That is what is really sad about this situation,' said the friend. The brothers have not always seen eye to eye. Rebecca has been hosting these wonderful Christmas and family gatherings where everyone has been included and she has healed rifts over the years. She bends over backwards to be hospitable. Nicholas Howard has made his reputation as a London-based photographer, with a home in the fashionable Bayswater district. He has photographed top artists such as Antony Gormley and Grayson Perry and his pictures of Castle Howard were exhibited at the house in 2008. Mr Howard married Victoria Barnsley, who created the publishing company Fourth Estate before becoming CEO of Harper Collins, in 1993, and they have a daughter, Blanche, 20. His son, George, is from his first marriage to Amanda Nimmo, the daughter of actor Derek Nimmo. The couple divorced in 1990. Its magnificent art collection includes ancient sculptures, Old Masters and works by Joshua Reynolds and Thomas Gainsborough Castle Howard was also the setting for the 2008 film version of Brideshead, which starred Emma Thompson, Michael Gambon, Matthew Goode and Ben Whishaw When Nicholas and his family visit Castle Howard as a guest of Simon and Rebecca, they are said to stay in rooms that he and his brother used as teenagers. Simon took over the running of the estate as a 27-year-old in favour of his elder brother Henry, who battled health problems and died in 2008. Earlier this year, the Castle Howard estate won a high-profile case against HMRC at the Court of Appeal, with a landmark ruling that the custodians should pay no capital gains tax on the Â£9.4million sale of a portrait by Sir Joshua Reynolds. Part of the 2001 auction sale went towards Simon's divorce from his first wife, Annette, that year. Rebecca has recently taken to spending a few days each week away from Castle Howard at a rented house on a neighbour's estate, which Simon also visits. The Howards say that with 250,000 visitors a year at Castle Howard, it is only natural that they would seek a bit of peace and quiet. Rebecca's induction into North Yorkshire country life has not always been smooth. An infamous 2002 article in Vanity Fair, penned by former friend Plum Sykes, described her as 'the woman who set out to marry a house', claiming she fell in love with Castle Howard after watching Brideshead Revisited in the 1980s. Simon took over the running of the estate as a 27-year-old in favour of his elder brother Henry, who battled health problems and died in 2008 In recent years the house has featured in the 1995 film The Buccaneers, and Garfield: A Tail Of Two Kitties The highly praised 1981 television adaptation of Evelyn Waugh's classic novel starred Jeremy Irons, Anthony Andrews and Diana Quick, and tells the story of the aristocratic Roman Catholic Marchmain family. It put the stately home on the international map. Castle Howard was also the setting for the 2008 film version of Brideshead, which starred Emma Thompson, Michael Gambon, Matthew Goode and Ben Whishaw. In recent years, it has featured in the 1995 film The Buccaneers, and Garfield: A Tail Of Two Kitties, released in 2006. It was also the exterior set for an estate in Stanley Kubrick's 1975 film Barry Lyndon. Earlier this year some of the castle's grand interiors were captured in incredible detail as part of the video sculpture, Breathless Beauty, Broken Beauty, by Vanessa Jane Hall, displayed at the Victoria and Albert Museum. Neither couple would comment when approached by The Mail on Sunday.