Oxford University professor Elleke Boehmer has written a book about former South African president Nelson Mandela to coincide with his 90th birthday celebrations next month.

The mother-of-two from the Waterways estate, North Oxford, started researching the book 18 months ago and it is being published on Mr Mandela's birthday - July 18.

Ms Boehmer, 46, is Professor of World Literature in English, and a Professorial Governing Body Fellow at Wolfson College. She flew to South Africa last Friday to promote the book.

Before she left, she said: "I'm over the moon about the Nelson Mandela book and I'm flying to South Africa to meet people from the Nelson Mandela Foundation.

"I was born in South Africa and the book is my own personal take on what makes Mandela one of the magical personalities of a miserable century.

"I have tried to analyse Mandela's charisma. Most people who have met him say they are touched by him.

"I have met Mr Mandela once and have seen him talk twice.

"In 2003, I met him in Cape Town when he was giving one of his big speeches about the Iraq war.

"On another occasion, about 10 years ago, I heard him give a speech at the opening of the Centre for Islamic Studies in Oxford and he spoke very convincingly about how Islam had always been a powerful force in Africa."

Prof Boehmer has also written a novella, Nile Baby, about a young girl living in England who starts to embrace her African roots. The story is about to be published by Ayebia.

Nelson Mandela - A Very Short Introduction is published by Oxford University Press, priced £7.99 Mr Mandela visited Oxford's Said Business School in 2002.

He received an honorary Doctor of Civil Law degree from Oxford University in 1996, above, and the Freedom of the City from Lord Mayor Bill Baker in 1997.

Mr Mandela will make a rare public appearance in London next month for a Live Aid-style concert to mark his 90th birthday.

The former South African president, who has retired from public life, will be joined by some of the biggest names from the worlds of pop and politics at the Hyde Park event, on Friday, June 27.

Performers are set to include Queen, the Sugababes, Dame Shirley Bassey, Razorlight and Jamelia.

In June 1964, Mr Mandela was sentenced to life imprisonment after being found guilty of plotting to overthrow the South African government.

He spent 27 years in prison before his release in 1990. He was elected as South Africa's first black president in 1994.