The author claims to be a 'non-Muslim historian' as though this gives him objective authority to truthfully research the history of Islam. Why he feels the need to highlight his non-Muslimness becomes apparent through the biased language he uses which draws obvious attention to the fact that he is anti-Islamic. I will draw your attention to the first chapter - perhaps the most important chapter.
"Such a reformed society needed an ideology and this was provided by a series of revelations Muhammad CLAIMED to have received from Allah ..."
The implication is glaring that the author feels that Muhammad was a liar who claimed to receive revelation to further his own ends - and does not consider the possibility that Muhammad believed he received revelation which would be a fairer assemssment in light of the evidence -
The author tells us a little later on -
"For the non-Muslim historian, though, there are numerous problems of validation, quite apart from the 'authenticity' of the Koranic revelation. No contemporaneous mention of Muhammad is made in sources outside of Arabia, for instance, and the closest sources we do have for his life and mission are invariably Islamic"
Again the implication is glaring that only western non-Muslim historians can write reliable history - and Islamic history will inevitably be biased towards Islam. I propose that the non-Muslim historian also writes biasly - example below.
My favourite folly of the author is the huge value judgement he then makes without facts - with regards to what I outlined above about evidence and validation;
"It is also likely - THOUGH IT IS NOT RECORDED - that he spends some of his time aquiring a knowledge of Jewish history from Mecca's small Jewish community"
Useful as a chronological guide but it is a shame rough guides have employed a second rate author to write about a great history.