Halfway through this tale of piety and plunder in the era of Oliver Cromwell, the reader comes across a telling one-liner from a Puritan divine. It was, wrote Hugh Peter in 1644, a ‘pamphlet-glutted age’. This was rather rich coming from Peter, a bigoted loudmouth who penned scores of tracts of his own, but no historian can disagree. As the Civil War reached its climax, so a torrent of print flowed from the presses on both sides. Few periods in English history have left behind so many sources, so much propaganda and such a welter of conflicting testimony from people with axes to grind.

For the scholar, this gives the 17th century a special fascination, but the writer of narrative history can often be overwhelmed by the sheer volume of words it produced. A vast amount of evidence survives, but is it reliable? How much of it is true? Did this or that battle