How about the Diary of Anner Frank, I read this when I was nine and it was definitely the book that made the biggest impression on me as a young person.

Claire, London, UK

As an avid reader since the age of six, I would suggest that books written for adults, in the main, are best read by adults with the experience to appreciate both the language and the content. My own experience is that any book which becomes compulsory reading, almost immediately becomes tedious.

Chris Quirke, Aylesbury,

How many well-educated adults can understand Leo Tolstoy's Anna Karenina, let alone a 13 year old girl? I am an undergraduate of the Russian language and read Anna Karenina at the age of about 17, and completely failed to understand it. Perhaps Jane Austen would be more accessible.

Helen Bolam, Sheffield,

I have to agree with Stephen Fry, this is wonderful story for ANY child under 13 to read : I was 10 (1964) when read this great story but I was also reading Dickens and Waugh around the same time and had no problems grasping the language. What has happened to our education system?

Mike Bromley, Kingston upon Thames, UK

I have to agree with Stephen Fry re Treasure Island, I read this wonderful story when I was 10 (1964) but I was also reading Dickens and Waugh and I had no problem grasping the language: I had read many of the classics by the time I reached 13. What has happened to the education system?

Mike Bromley, Kingston upon Thames, UK

A bishop and a reverend recommending the bible? Never!

James, Bath,

By the age of 13 most children will have done little reading other than that required for school. To get them to read anything at all is the challenge, rather than The Bible or Anna Kerenina. The 39 Steps would be a good start though.

David Leslie, Perth, Scotland

My daughter (now in her 20s) has loved books since she was a baby, was and remains an omnivorous reader from childhood. Yet she still, at 13 or 14, found that Lorna Doone required considerable reading stamina and perseverence.- I think even she might have found Anna Karenina a bit too much!

Gill, Southampton, UK

I don't think Treasure Island or the 39 Steps are too challenging - I had read those by the age of ten (I'm in my mid 20s now, so it wasn't THAT long ago).

Anna Karenina seems a bit harsh though! I think girls can be trusted to read the same books as boys really....

Nick, London,