Any work of history is bound to have a few errors of fact or interpretation, but "A World Lit Only By Fire" is riddled with astonishing inaccuracies. At one point, Manchester claims that Copernicus was burned at the stake by the Inquisition. In fact, Copernicus died of natural causes (cerebral haemorrhage) in 1543! Publication of his "Book of Revolutions" was actually encouraged by certain Church officials during his lifetime, and the book was not proscribed by the Church until 73 years after it was published. Perhaps Manchester was thinking of Giordano Bruno, or perhaps he was not thinking at all. Another example: His description of John Calvin's bloodthirsty doings relies on heavily biased secondary sources, many of which have been discredited by serious historians. There's no need to bring up further examples, since Manchester himself claims in his introduction that a historian who read the manuscript disagreed with statements on almost every page of this book. It seems safe to assume that Manchester's unwillingness to correct or qualify these statements was the result of his having an axe to grind. If you have even a glancing acquaintance with medieval history, you'll be shocked by Manchester's willful disregard for basic facts. If you're new to the subject and want a good introduction, try Barbara Tuchman's "A Distant Mirror" or Norman Cohn's "Pursuit of the Millennium."