FOR A BALDING 55-year-old with a paunch and a metal spine, Julian Fellowes is a disgustingly happy fellow. The self-styled King of Class, he's the overnight darling of Hollywood. If you want to know how to hold a teacup or why it's irredeemably vulgar to say 'mantlepiece' - apparently one should say 'mantleshelf' - he's your man. Americans just adore him. And they're not alone. Gosford Park won him an Oscar, his novel Snobs, newly released in paperback, is a best-seller and his long-legged wife, Emma, is lady-in-waiting to Princess Michael of Kent. He is truly a toff's toff. A great big Bentley of a man, his vowels are as immaculate as his fingernails. Encased in blue blazer and green corduroy he looks entirely at home amid the heavy family oils that litter the walls. No less than three rivers run through his sprawling estate. But it wasn't always so. When he wrote that screenplay, he was 52, staying in a boarding house in Inverness, Scotland, ekeing out a career acting in light television, notably the buffoonish Lord Kilwillie in BBC's gently amusing Monarch of the Glen. Since then he's worked relentlessly. He rewrote the screenplay for Vanity Fair, and wrote the stage adaptation of the hugely successful musical Mary Poppins, and his latest film Separate Lives - which he wrote and directed - is being released this summer. There is, it seems, no stopping him. 'If I'd been born 15 years earlier, success would have come sooner, I think. For the generation before me, it was an advantage to be posh. For my generation it was a disadvantage. But now it's neither and I do think that's best. 'But I've had a pretty good run. Not because I'm posh or well-educated or Tory, but because it all started happening in my 50s. I'm everybody's last-ditch fantasy - proof that's it's never all over.' For years Fellowes tootled along playing doctors and clergymen and bank managers. He even tried his hand in Hollywood. 'But when I found myself waiting by the phone to hear if I'd got the part of a comedy butler in Fantasy Island, I decided enough was enough and came home.' Dispirited, he turned to writing. At first, bodice-rippers under the name Rebecca Greville, who ostensibly lived in Surrey and bred borzois, until a newspaper exposed him as a struggling actor forced into a Mills and Boon subterfuge to pay the bills. And so he started writing television adaptations, winning an Emmy in 1995 with Little Lord Fauntleroy. But it was a long haul. 'I wrote something like 20 scripts before Gosford and none of them was made. You're sending off these manuscripts, writing these letters, banging on doors, and you just think, 'Oh, god, is anything ever going to happen?'.' But Fellowes is a master at seizing the second chance. So, too, a wife. 'I was ugly as a young man and that held me back. At Cambridge I was the laughing fool by the drinks table that no one wanted to get off with. I just wasn't seen as boyfriend material. When I was 34, I was really up for marriage. I thought I'd missed out. Up until 30, some of your friends are married, some not. By 35 you're looking round desperately, thinking, 'My god, everyone's married.' I'd go to parties and be the life and soul, but go home and be in an absolute black pool of depression.' His life changed, at last, when he met Emma Kitchener - the great-great-niece of Lord Kitchener of Khartoum - at a party. He was 39, 14 years her senior, but he had no doubts. 'It's the only psychic moment I've ever had. I just thought: 'She's arrived, after 39 years, she's here.' She was wearing a dark green dress with bobbles like candlewick and an Alice band. I knew I was going to marry her from that very first second. I proposed 20 minutes later.' Seduction was not, however, to prove quite that simple. It was Friday 13th and Emma went home and wrote in her diary: 'A funny little man asked me to marry him.' She refused to give him even her phone number. But Fellowes is not a man to give up easily: 'One of the few lessons I've learned is that tenacity is the great virtue. I have known lots of people who have been successful. Some of them have been very talented, clever or beautiful, some not at all. But they were all tenacious.' He laid siege and, 11 months later, asked her again. 'I'm as ambitious as Stalin and your emotional life is what counts. Ignore it at your peril. We went out for a walk and I hurled myself on my knees in the mud as I held out the ring. I'd run my race. I knew that if I didn't get this particular girl I would never meet anyone who was so right again. This was the one.' At their wedding reception - at the House of Lords - he described theirs as a union between the 'man with no future and the woman with no past'. He is nothing if not a hopeless romantic. Fellowes, the youngest of four boys, was devoted to his fearsomely strong 'upper middle-class' mother, who died in 1980, aged 62. And he respected his 'lower upper' father, a diplomat - so much so that he even named his 14-year-old son Peregrine after him. 'There has always been a Peregrine Fellowes in the family since 1760'. But they were never, one suspects, close. 'My father was wholly unworldly. I'm much more like her.' And, as with so many men with strong mothers but weak or distant fathers, there's a certain campness there - girlishness even. He speaks so winsomely of love. It's rather touching. 'I don't fall in love easily. I fell rarely and deeply - I can't think of anyone in my life whom I have loved who I do not now love. I'm not in love with them in the same way because I am in love with my wife. But there's not a single one who, if she needed money or help, I would let down. 'I've been very lucky. I've been a good chooser and chosen jolly nice people to love, which I think is rather a feather in my cap.' He looks quietly pleased, seemingly surprising himself by this revelation. How many times, then, has he been in love? 'Oh, four or five. I'm rather glad I'm settled now. That whole business of feeling sick when the telephone rings, driving around in the dark and all that. Dreadful.' He's evidently a very good egg, indeed. His mother-in-law lives with him and Emma on their Dorset estate. She insists on calling him Evelyn. And he plays along happily, which shows inordinate sweetness. 'There was an Evelyn - a family friend she was devoted to,' he says. 'And in her dreams she would have loved him to have married Emma. There comes a point when, if you can't beat them, join them. As my mother used to say, 'In marriage, only have the important fights.' It's a pretty good rule for family life.' One ends up with the face one deserves. And Fellowes, pinkly scrubbed and ridiculously unlined, is eminently likeable. He looks like a cross between a country surgeon and a gentleman butcher. He even makes Princess Michael - godmother to Peregrine - sound less than ghastly. 'I like people who are painted in primary colours,' he says. She, in turn, lauds him as 'the man with the quickest, sharpest yet kindest wit in London, a cultivated, cultural snob - an expert without being one.' But for all his easy bonhomie, he's clearly far from easy to live with. Until his marriage, he'd never lived with a woman before. 'I'd never known the extreme intimacy of cohabitation. I'd been an adult on my own for 20 years. During our engagement, we gave a dinner at my house and Emma put out the wrong service for the first course, which riled me.' Crikey. 'There's an age where you just slide into this bachelor person and 39 was nearing the cusp. But I heard this voice in my head that said, 'If you can't deal with different plates, you're in big trouble.' 'So I simply said to Emma, 'Could you just leave the library alone?' I accepted that my life was going to change, totally. And it did.' What makes him such a keen observer of upper-class mores - the motif of Gosford Park, Vanity Fair and Snobs - is that he's undeniably posh, but not too posh. One interviewer likened him to hoi polloi, which is going rather too far. But he has, on occasion, bought his own furniture. His wife is, arguably, posher. 'Technically, she is, yes,' he says, without rancour. 'She's the niece of an earl. She's got Khartoum, I've got Cadiz.' His ancestor was Rear-Admiral Sir Thomas Fellowes, who commanded the gunboats in 1810. 'I think my family is more interesting in the main, but Kitchener was such a giant of history. It's rather like saying, 'What are the Bonapartes without Napoleon?' I have more, but less. I think it balances out quite nicely.' Belated success - and happiness - clearly suit him. As he says: 'Frustration is the seedbed of achievement and ambition. To fall happily and mutually in love at 20 and to be received and wanted by the object of your desire is probably rather flattening.' Julian Fellowes is anything but flat.