Her maternal grandparents were, in her words, "Hungarian-speaking-Czech, Ruthenian for about 10 minutes, Carpathian mountain-y, impossible to describe", who left Prague in 1939.

She was born in 1972 in west London, in a flat on the Queensway. When she was two, she moved with her parents and her baby sister to a house in a cobbled passage next to St John's College, Oxford, where her father taught public international law.

She took up the French horn because it has a reputation for being the hardest instrument to play.

After the King's School, Canterbury,she studied Ancient and Modern History at the University of Oxford, even though she knows now, with great regret, that what would have suited her best was English literature at somewhere like Leeds.

She says she became a lesbian suddenly. "It was boyfriends up to 22 or 23. Not a whiff of lesbianism. Not even a thought. But I'm very all or nothing. It was all that, and now it's all this. There was about a 10-minute cross-over period of uncertainty, but it was really not that bad."

She has two children with the journalist and novelist Joanna Briscoe.

She wrote her first short story, ‘Blood Sugar’, at the suggestion of, with the encouragement of, submitting to the insistence of her tutor Craig Raine. It was published in Granta's New Writing 7 and twice broadcast on BBC Radio 4.

Her first novel, Love in Idleness followed in 2001.

She won the John Llewellyn Rhys Prize in 2003 and the Somerset Maugham Award in 2004 for her second novel Daughters of Jerusalem. She was shortlisted for the Sunday Times Young Writer of the Year Award in 2003.

Her third novel, When We Were Bad, was published in May 2007.

She contributes regularly to the TLS, the Guardian, the Independent on Sunday and the Observer. She is an editor at the publishers Headline Review.

She was placed 60th on the Independent on Sunday Pink List 2007. [1]

Mendelson was among Waterstones' 25 Authors for the Future - twenty-five writers "predicted to keep us entertained, enthralled and informed over the next 25 years. There were more than 100 nominees from publishers, editors and agents asked to select the emergent British writers of the 21st Century who they believed would go on to produce the most impressive body of work over the next quarter century. The final 25 were selected by a panel at Waterstones She also featured in the Harper's Bazaar list of emerging writers Forty under 40, which commented Hailed as a new star of writing well before her first novel was published, Mendelson has risen above the hype to forge a substantial career...We think Mendelson is ready to join Zadie Smith and David Mitchell in Brit's big league.