The title is absolutely killer. Pity it wasn't used on a better book.
A World Lit Only By Fire is about the transition from the medieval world to the Renaissance one, focusing on how the rise of Protestantism shattered the medieval worldview's unchanging conceptions of the world and man's place in it. The book offers a reasonably detailed account of the Reformation, and how its flames were fanned by anticlericalism and budding nationalism, but I don't think the author does a great job even staking out a thesis, let alone defending one. He couldn't seem to make up his mind whether he was explaining history or merely describing it.
Once upon a time, in our Land of Khalifia, there lived a King and his Archmage.
Seeing that their birthdays were close together, the Archmage proposed a shared celebratory festival, reasoning that guests would be more grateful for one spectacular event than two lesser ones. The King agreed at once. After consulting the almanac for auspicious days, they fixed the date of the festival for the 24th of August, and invited noblemen, dignitaries, and a few select members of the landed gentry to eat, drink, and be merry.