Cuthbert Collingwood was in need of a biographer, not only because he was Nelson's best friend and, after Trafalgar, his successor, but because he then became historically significant in his own right. So, at a time when publishers are calling for yet more biographies of the charismatic Nelson, it is good to read about Collingwood, who was in some respects his opposite, and far more difficult to define.

We know more about Nelson than perhaps any other major historical figure thanks to the prodigious number of letters he wrote, which illuminate so many complexities and contradictions that his biographers can pick and mix to fit their own theories. Collingwood's prose was as good as Nelson's but his letters