Sebastian Barry talks family, hope, danger, despair and Ireland

The novelist uses fiction to understand characters in his own family. He just didn't know how right he was.

"What is being Irish?"

The celebrated Wicklow novelist Sebastian Barry, longlisted for the 2011 Booker Prize, isn't having an existential crisis. He's trying to work out why his celebrated, award-winning books often seem to return to the same themes: family, hope, danger, despair and Ireland.

"I've written these books realising that I was bringing up my children in an Ireland that I didn't really know. And you have to try to understand where you're from, don't you? I mean, it's like a state of emergency in the individual if you can't."

All of which sounds like one of the many lyrical sentences from his books, but Barry is engaging, down-to-earth company. He even jokes about the success of his last book, The Secret Scripture - "which won the Costa Prize despite the judges criticising it!" - and is not in the least bit upset that it lost out to Aravind Adiga at the 2008 Booker Prize (the second time he's been shortlisted).

There's every chance that his fifth book, On Canaan's Side, will go one better - if only because it refines the potent, urgent storytelling of The Secret Scripture. In fact, the two stories cover similar ground. In The Secret Scripture, a 100-year-old woman decides to write an autobiography of her tough, violent life in Sligo, Ireland. On Canaan's Side begins with Lily Bere, 89, similarly determined to make sense of an existence beset by misfortune and drama. The opening chapters find Lily tormented by grief as she struggles to cope with her grandson's death after the Gulf War. As she tries to understand her loss, her own fugitive life in Ireland and America - played out across the entire 20th century - spills out on to the page as she, somewhat begrudgingly, writes down her thoughts.

"I wanted to make it feel that no one might ever read her story." says Barry. "But that wouldn't matter because in writing it, Lily would understand her life. That was important. I know this better than most: thinking about something and actually writing it down are two radically different practices, often with different conclusions. So Lily can, in a way, meet herself by writing about her life. She can see what and who she is with clarity."

And Barry had a vested interest in finding out, too, because Lily is actually his great aunt. He first wrote about her in a play called The Steward of Christendom, and members of her family appeared in Annie Dunne and A Long Long Way, his other Booker-shortlisted novel. What keeps drawing him back?

"Well, I love Victorian fiction and its preoccupation with revealing secrets," he says. "And everybody in my family, for some reason, had a secret. Lily's father was the chief-superintendent in the Dublin Metropolitan Police before independence in the 1920s, and so her family were in a very dark and dangerous place - the wrong side of history. I knew that Lily had to leave Ireland for America but imagined it was because she couldn't bear the fall in status and social disgrace.

"And then a cousin came up to me at a reading and told me about this unknown brother, Jack, who went with her but was gunned down in the street in Chicago by the IRA. This happened quite a lot, but when it's in your own family, when no one has spoken about it and your own father doesn't even know about it ... that's an enormous thing. It was covered over - my uncle always thought he'd gone to America and had died in a reservoir accident."

This isn't exactly how the events turn out in the book, but for Barry, that doesn't matter. His voice lowers to a whisper as he tells me that, just last week, he was browsing a bookstore and came across a non-fictional account of the period where, incredibly, Lily's presence on an IRA blacklist was detailed.

"It meant that I was right, that Lily hadn't fled to America in despair, but terror. To read your great aunt in this book, to find the strange corroboration between the made-up story and the truth was really quite shocking. And for a novelist it's incredible - it's like a strange message from the past."

Part of the reason Barry's work is so readable is that he sets such personal history within the wider sweep of the 20th century, without getting bogged down in the specifics of world wars and presidential assassinations. He does so, too, with a rare, moving poeticism. History seems to happen around Lily rather than specifically to her: a marriage to a policeman has a complex racial dimension that is only truly explained in hindsight - but refers obliquely to the civil rights movement of the 1960s.

Barry refuses to get vexed about his lack of a Booker Prize thus far. If he's passed over again, it won't grieve him too much.

"It's like boxing: the belt isn't taken from the loser - somebody wins it. And writing is like boxing. You take blows along the way. It's a hard profession and it's fantastic to see someone bearing their scars getting that belt - whoever it is."

Still, Barry deserves another shot at the title.