The book's focus is the Crisis of the Late Middle Ages which caused widespread suffering in Europe in the 14th century. Drawing heavily on "Froissart's Chronicles", Tuchman recounts the histories of the Hundred Years' War, the Black Plague, the Papal Schism, pillaging mercenaries, anti-Semitism, popular revolts including the Jacquerie in France, the liberation of Switzerland, the Battle of the Golden Spurs, and various peasant uprisings. She also discusses the advance of the Islamic Ottoman Empire into Europe, which ended in the disastrous Battle of Nicopolis. Yet Tuchman's scope is not limited to political and religious events. She begins with a discussion of the Little Ice Age, a change in climate that reduced average temperatures in Europe well into the mid-19th century, and describes the lives of all social classes, from nobility and clergy to the peasantry.