It sounds similar to one I read a few years ago, "and did those feet" by Charlie Connelly. The author is an inexperienced walker, relies on his friend to choose equipment and sets out on walks that trace historical British events, in one of the chapters he walks from Norwich to London as Boudicca and her followers apparently did, in another he goes to Isle of Man to learn about King Olaf, in another he finds a monument to the secret queen of Wales; young girl was heir to the Welsh throne was kidnapped and placed in a convent in England.
It's less than £3 here if you're interested. http://www.amazon.co.uk/gp/offer-listing/0349120889/ref=dp_olp_new?ie=UTF8&condition=new