In the late 1970s, the novelist Joseph O'Connor was growing up in a southside Dublin suburb that centred on a single, grand house. That residence had been, years before, the home of the rich family who once owned the surrounding land; many of Dublin's southside housing estates sit in a kind of orbit around such monuments to the city's recent history. In the case of O'Connor, though, proximity to this house in particular proved fateful: it had belonged to the family of the great Irish playwright John Synge.
"Growing up, our mother was always telling us stories about Synge," O'Connor tells me. "Here was this great, doomed genius of the Irish upper class, and he was a local hero. "The first play I ever saw, aged eight or nine, was by Synge. Along with Yeats and Wilde he was a part of the Easter Island of Irish literature, looming at us. The stories about Synge cast a spell." Thirtysomething years on, that spell has become O'Connor's latest novel, Ghost Light. This new book comes after the vast success of 2003's Star of the Sea, which was elevated into the popular consciousness by former literary kingmakers Richard and Judy - the passing of their TV book club is much lamented by British publishers - and which went on to sell a million copies. Star of the Sea's success drew O'Connor - older brother to singer Sinéad - to the forefront of a generation of Irish writers that includes internationally known names such as Colm Toíbín and Roddy Doyle.
The 46-year-old could have been forgiven for luxuriating in his success; no doubt his publisher would have welcomed a sequel to Star, which tells the story of a ship as it sails from Ireland to the USA, carrying refugees from the Irish Potato Famine. Instead, he sought out a new artistic challenge: to render in fiction the story about John Synge that mesmerised him as a child - and to move away from the self-consciously epic mode of Star towards a spare, lyrical writing that best suited this new material.
Ghost Light tells the story of Synge's love affair with the Irish stage and film actress Molly Allgood, which culminated in their secret engagement in 1906. Their shared history is not a happy one. Synge and Molly never married, and three years after their engagement Synge died of Hodgkin's lymphoma. Today, O'Connor is sipping coffee in a smart, high-ceilinged cafe in London's West End, and reflecting on how a boyhood fascination became the newly-printed hardback that sits in front of him.
"Synge was a member of the Anglo-Irish Protestant upper class, a difficult, awkward man, and Molly was a working-class Catholic girl full of Dublin humour and cheek. So this is a story about the difficult relationship between England and Ireland. It's a story about class in Ireland. But foremost it's a story about falling in love." The opportunity to write a different kind of love story to those often encountered in fiction was a part of the attraction. "Many novels, from Jane Austen to Bridget Jones, tell love stories that are built around marriage," he says. "What about the relationships that are a crucial part of your life, but don't work out? The relationship might end, but you carry that other person with you for the rest of your life. We all have someone like that. And Synge was that person for Molly."
To tell this story, though, O'Connor first had to retreat into the archives. Synge was born into a landed Anglo-Irish family in 1871; his father, a barrister, died a few months after his birth. Best known for his 1907 work The Playboy of the Western World - which sparked riots at its debut, due to what audience members felt was an obscene depiction of Irish rural working-class life - Synge was just 37 when he died, having achieved only limited recognition.
"Synge was a difficult character in so many ways," says O'Connor. "Seamus Heaney said of him, 'Loneliness was his passport through the world'. "He was too English for the Irish, and not English enough for the English. Even his ferocious intelligence seemed to bring him unhappiness when he rejected the dogmatic religion into which he'd been raised. "His puritanical family loathed the theatre, and never sat through a single one of his plays. There was this deep vein of reticence and awkwardness that ran through him. But then he falls in love with the last person you'd expect him to fall in love with."
But writing Ghost Light, says O'Connor, meant discovering that - despite the rich fictive possibilities afforded by Synge's character - the book belonged to Molly. "I had a few goes at this novel in which Synge told the story," remembers O'Connor. "But eventually it became clear that whenever Molly stepped on to the page, the book really came alive. My last two books had a symphonic feel; I wanted this book, instead, to have a spareness, a purity.
"The solution was to narrow my focus to one day in Molly's life, as she moves across London and looks back at this great affair. Molly died in relative obscurity and her grave here in London is fairly unloved, so it's wonderful to be able to write about her. But this isn't an account for historians; I've played with the story. I'm sure Synge and Molly - being storytellers themselves - would understand."
Some critics have seen Ghost Light as the last book in a loose "Irish trilogy" that began with Star of the Sea and also takes in Redemption Falls, which tells the story of an Irish revolutionary in the American Civil War. Indeed, these days O'Connor finds himself called a leading practitioner of "Irish fiction". It's a tag, he says, that he doesn't find meaningful: "I just don't think of writers in that way. I think of my favourite writers as my pals, guests at my own private dinner party. Nationality doesn't come into it."
Still, it's an unexpected career development for a writer whose first novel, Cowboys and Indians, was set in London, and his second, Desperadoes, in Nicaragua. But O'Connor is by turns grateful for the huge success enjoyed by Star, and philosophical about the peaks and troughs that are a part of any literary career. "The great irony of my writing life is that the book I wrote as a labour of love, Star, ended up changing my career like this. I thought it would be read by about seven people, and then my publisher would quietly have me shot. Instead, Richard and Judy intervened.
"What happened with that novel was amazing. At its peak it sold 38,000 copies in one week. It was a wonderful thrill, but any writer would be wise to get over it fast. Pretty soon, it will be you and a blank notebook again." Ploughing his own creative furrow alongside such a famous sister has also, surely, inculcated in O'Connor a healthy scepticism on the value of literary fame? "In the mid-90s, a friend in Australia wrote to me to tell me he'd seen a review of one of my novels in an Australian newspaper. He'd cut out the review and sent it. The headline read: 'Sinéad O'Connor's brother writes novel.'"
If commercial success didn't change O'Connor's consciousness as a writer, though, he says that a new attitude to his fiction that began with Star certainly informed the writing of Ghost Light. "Star was the first novel I wrote that I was absolutely committed to, and I've carried that into all the subsequent novels. I poured everything into Ghost Light; into achieving a spare, lyrical prose, and the right structure.
"I've come to realise that when it comes to fiction, it's the reader who performs the most creative act. You can play with their expectations, or subvert them, but you'd better be mindful of them. The reader must have an absolutely central part in your life. There are enough quite good novels in the world. I want to write something that will last a few years." Ghost Light by Joseph O'Connor is out now. (Harvill Secker)