The Tennants may not be Britain's oldest or richest family but they are a colourful lot, even today: the best-known scion of the current generation is the supermodel Stella Tennant. Then there is Colin Tennant, Emma's eldest half-brother, Lord Glenconner, who bought the island of Mustique in 1958 for pounds 45,000, and turned it into a holiday playground for the likes of David Bowie and Mick Jagger - and Princess Margaret, a close friend to whom he gave a plot of land on the island as a wedding present. (Mustique has now been sold, though Colin still lives in the Caribbean.) It sounds an idyllic existence - but there is a background of extraordinary tragedy.
Colin disinherited his eldest son Charles from the family succession at the age of 21, because of his addiction to heroin (Charles, who died of hepatitis in 1996, aged 39, once sold private pictures of Princess Margaret in fancy dress to raise money to feed his habit). The estate was made over to Henry, his second son, who later died of Aids-related illness. And the youngest son, Christopher, was brain-damaged in a motor- cycle accident. No wonder perhaps that there have been mutterings of a curse on the family - something Emma Tennant today rebuts with vigour. "The curse was invented by the tabloid press, maybe 15 years ago. A lot of old families have very distinguished curses, which have gone on for ages, where people see three white foxes or hear an owl hoot, but this was invented by the tabloids. It was cooked up when somebody's wretched children were ill and dying ... Incredible really."
Emma Tennant, now 60, has lived in west London since the mid-1970s. But though she has made only brief visits to Glen in recent years, the house - now the property of the unfortunate Henry's widow, Tessa - looms large in her new book, Strangers: A Family Romance. The book, like the house, is peopled with Tennant beauties, her grandmother Pamela, great-aunt Laura and aunt Clare among them, but she made no concessions to glamour on the day we met, dressing in a comfortable jersey skirt and voluminous sweater, with hiking boots and thick socks. Although she has often been asked to write about her family, it is only recently that she has been able to bring herself to lay to rest the ghosts of Glen. "Quite a lot of people wanted me to write about my family, I suppose for fairly obvious reasons, and there was always something that would stop me, I thought they were asking me for the wrong motives," she says. She describes Strangers as a novel - but it features real people, and is, she acknowledges, a "peculiar mix of fact and fiction". Emma herself joins the cast halfway through the book, appearing at the age of three - but the real starring roles are taken by her grandmother Pamela Tennant, her great-aunt Margot Asquith (nee Tennant) and Pamela's children, Emma's aunts and uncles.
PAMELA TENNANT, a great beauty and femme fatale, married (unhappily, suggests Emma in Strangers, though it is often hard to separate speculation from fact in the book) to Edward, the first Baron Glenconner, is one of the pivotal figures of the book. "Somehow," writes Emma, "the accepted view of Pamela is that she is the villain of the piece. Everything bad that befalls the family can be traced back to her. A cross between the Whore of Babylon and the Madonna, my grandmother was fated to suffer the scorn of posterity." Emma herself takes a kinder view. "I think Pamela was blamed for all the narcissism and dottiness that came out in the family afterwards, but I'm not sure she was really responsible," she says. "Before, the Tennants were thrusting Scots, and you can't get much more thrusting than a thrusting Scot. But the family married into the aristocracy, and the view was that if they hadn't done so they would have carried on thrusting. But I'm not sure they would."
Pamela, she says, had French royal blood as well as Irish nobility in her - a far cry from her in-laws, who made their fortune in Victorian times when a yeoman farmer called Charles Tennant invented bleach. Pamela's children, known in the family as her "jewels", were her passion and her obsession. Edward, her eldest son, known as Bim, born in 1897, was the apple of her eye. "I'm sure everybody was in love with Bim," says Emma. "You can see why from the photographs. It was always known that he was the one Pamela was completely obsessed by; it was the fact that he looked so like her own family, and so unlike these Tennants that she'd condescended to marry into, and he was obviously so charming and clever and sweet." Bim died at the age of 20 on the Somme; Pamela's heart was broken and she turned to seances and spiritualism in the hope of contacting him beyond the grave.
It was Bim's death that led to his younger brother, Emma's father Christopher, inheriting Glen (Emma's own parents seem to have been a rock of stability in the maelstrom of eccentricity that was the Tennant family, perhaps because her father left early on for Dartmouth Naval College). But if Bim and Christopher were the flowers of the family, the rest of Pamela's "jewels" exhibited a rare range of peculiarities.
The older daughter, wilful, beautiful Clare, born in 1896, was Emma's wicked aunt. When her devoted husband wrote to her from the front, she ignored his letters as she partied through the First World War. She danced every night at Ciro's, writes Emma, and staggered home "exhausted, hollow- cheeked, burning-eyed from the ragtime", while her husband's hopeless letters piled up in the hall. Clare eventually, and scandalously, divorced and re-married three times. Pamela's third son, David, meanwhile, ran nightclubs in London, including the bohemian Gargoyle Club, hung with Matisses, where "there is neither night nor day; and as there is no sense of recorded time, it is always the hour to have a drink".
But perhaps the oddest of all Pamela's children was her fourth and youngest son, Emma's uncle Stephen. Stephen, beautiful in his youth, artistic and gay, took over his mother's beloved estate at Wilsford in Wiltshire, and added a reptile house, an aviary and all-white decor, including a white piano and polar-bear-skin rugs. "Stephen in his parrot house, where the birds fly from his shoulder to perch on Bright Young Things welcome to partake of this most artificial and temporary of hospitalities," describes Emma. "Stephen at an upper window, dressed in gold and silver lame ... hits the headlines with a succession of parties - and later, a love affair with Siegfried Sassoon." Stephen grew old, plump and increasingly eccentric at Wilsford. Women visitors were unwelcome and were likely to be shown the door, although, says Emma, "he would see people like David Hockney who came down from London. It became a shrine for young, talented gays."
Emma, who used one of the cottages on the estate as a refuge from London, plucked up courage to visit the house in 1965, but didn't meet her uncle. "The fact that I was not greeted downstairs has already confirmed my suspicion that he has no desire to see a niece, particularly one who might make a habit of coming over and disturbing his peace." Or his beauty regime; Emma recalls her eye catching an entry in an open diary: "Rest the eyelashes for a month. My resolution: no mascara, no eye pencil ..."
Stephen's aunt, Margot Asquith, although she was an opinionated and politically influential woman - married to Herbert Asquith, Prime Minister during the First World War - cuts a surprisingly poignant figure in the book, "thin and bony as a stickleback". Her stepdaughter Violet's best friend, Venetia Stanley, achieved "the theft of her [Margot's] most valuable possession of all, the Prime Minister's heart". Margot reappears years later, when Emma is a little girl at Glen, so bony by now that "her nose and chin almost meet", sweeping up to the front door and then doing an abrupt turnaround to brood by the loch instead - much to the surprise and slightly alarmed amusement of Emma's parents. Emma imagines that Margot has gone to commune with the spirit of her beautiful, long-dead sister Laura Tennant.
Still, such apparitions were less alarming than the 1952 visit of Princess Margaret, casually announced by Emma's oldest half-brother, Colin Tennant. This visit necessitated the hiring of a butler from Edinburgh, to help the few servants who were kept on as the castle was gradually run down after the Second World War. There was a flurry of cleaning and preparation and general panic. Emma's younger brother, 11-year-old Toby, was carefully drilled in how to announce a telephone call to a royal personage. "On no account say, 'Your mother is on the phone'," hissed an apprehensive Colin. "Say, 'Excuse me, Ma'am, her Majesty Queen Elizabeth is on the telephone'." Emma suggests that Colin may have intended to propose to the princess, but was dissuaded by their father. His "close friendship" with Margaret brought the tabloid press flocking; but any romance came to nothing in the end.
Did Colin ever intend to propose to Princess Margaret? Was Margot Asquith secretly heart-broken? Was Pamela really a broodingly neurotic mother? Who knows? Emma Tennant makes no excuses for her use of artistic license in Strangers. "If you shut your eyes and imagine you're writing about your grandmother or your aunt, there's a good deal of you in her, there's got to be," she says. "People had talked over the years about them, so I felt I did know them. I suppose it had just sort of gone into the pores of my skin. And I felt I had a certain moral authority because they were my family. I wanted to bring them to life and show them talking, but the way it is done, in a series of scenes, it's not as if I had to invent a plot and put real people into it, which I think would be wrong."
As well as using her imagination, she drew on family letters and photographs - and, as she says, there was plenty of contemporary documentation already published, to consult. "I think I rather dread in reviews people saying: 'How do we know what's fact and what's fiction?' For example, Margot Asquith's views on Home Rule and universal suffrage are in her diaries, which are available from any library," she observes tartly. Her aim, she says, was to capture the atmosphere of the time. "The book is, apart from some invented conversations, as accurate to the feeling and to what was happening at the time as is humanly possible." After reading the first chapter, her mother encouraged her to go on. "She wasn't there at the time - she was too young - but she was almost there ... When she said, 'I think you've got it right', I was very encouraged."
Writing Strangers, she says, was highly cathartic. "I felt very upset when I was writing it, and not for my own childhood or my own memories. I felt more for the ghosts of the past. I think it's because I spent so much time isolated up at Glen. The atmosphere of the place came back with a tremendous thump when I realised that finally the time had come to sit down and try to write about it."
GLEN, PARTIALLY shut-up during the Second World War, never returned to its former glory of prolonged visits, shooting parties and myriad servants. After the war, an attempt was made to revive it as the family home but, recalls Emma, who by then was at school in London, "We helped ourselves from a hot plate in the dining room and shivered before pale, one-bar electric fires." And yet she still loved the place. "It went without saying," she writes, "that Glen had to remain in the family - even if, as I saw with ever- increasing dismay, each member of that family hated at least one other with all their heart. Were all families like this? The school friends I made seemed not to be afflicted as I was. They lacked a 'glorious past' (my half-brother James's bragging speciality) and had many fewer divorces ... Drink, in the shape of my uncle David, whose one visit [to Glen] had him crawling to the brandy tray, at the shock, no doubt, of being away from London and the Gargoyle, didn't figure high on the list of my friends' families' sins. Stephen was unlikely to remind anyone of their uncles ..."
The younger generation of Tennants, Emma says, are less given to feuding. Her own three children get on well with their cousins, who include the famous Stella (daughter of the same Toby who was tutored as a child in answering the phone to royalty). "This generation seems absolutely fine - but no one's been sitting at Glen at all. There just isn't any nucleus now, like there was then. There was my father. He couldn't be there all the time because he was working in London. But he was doing his best to be a kind of benign patriarchal figure. Now there isn't any kind of headquarters. My younger brother Toby has rather taken on my father's role and has relatives to stay in the farmhouse he lives in in Roxboroughshire; he certainly provides a nucleus, but not at Glen, you see."
At the end of Strangers, modernity breaks in suddenly. Emma is visited by her nephew Henry, Colin's second son, "immensely tall, thin and feverish, an Aids victim in need of advice and help". "I thought," she says a little sadly, "the book would end with a feeling of the impossibility of fantasy. That place, and the family that had lived there, were a well-spring of imaginative fancies, if you like. Henry did seem to bring the thing full- circle and gives a jolt; it brings in this awful modern disease." Modernity has encroached in other ways too. Glen is now being managed as a conference centre, with just a few rooms left for the family's occasional use. Its influence as a magnet and inspiration for the family has waned. Emma's feelings about it now are ambivalent. "I wonder ... how I could possibly have spent my childhood, often almost on my own, in this fantastical Disney castle, forbidding, frivolous and cold."
But even with Glen reincarnated as conference centre, there are still a few ghosts about. One of Emma's fictions in Strangers is a character called Louisa, one of the maids at Glen, secretly and hopelessly in love with Bim, whose sensitivity to the spirit world is discovered by a grateful Pamela, who presses her into helping contact Bim at seances. Louisa is the only figure to recur throughout the book, a thread that pulls everything together. "While I was writing the book, I read, rather spookily, that Pamela did have this Scots maid that she would take down south for seances. I had no idea. It's very odd - the way that fact and fiction feed each other."
The flamboyant Stephen Tennant died in 1987. "A Mr Darcy bought the Wilsford house - terribly funny," says Emma with a great laugh (one of her best- known works is Pemberley, the continuation of Pride and Prejudice). "The builders had to have the house exorcised, because there was a man wandering the upper floors, the ghost of Stephen. I can well believe it. There is a lot of haunting going on somewhere still."
! 'Strangers' is published on Thursday (Jonathan Cape, pounds 12.99).