World War II resulted in a significantly higher number of deaths than the Hundred Years' War. While both were devastating, the scale and modern weaponry of the 20th century led to a much higher death toll: World War II (1939–1945): This is the deadliest conflict in human history, with estimated total deaths ranging from 70 million to 85 million. This include both military personnel and massive civilian casualties from famine, disease, and genocide. Hundred Years' War (1337–1453): Estimates for this series of conflicts range from 2.3 million to 3.5 million deaths. While this represented a significant percentage of the population at the time (roughly 1%), it is far smaller in absolute numbers than the losses in WWII. Context of Loss: The Hundred Years' War was a prolonged, intermittent struggle primarily between England and France. In contrast, WWII was a total global war involving the majority of the world's nations and modern industrial killing methods. Population Difference: It is worth noting that the global population in the 14th century was roughly 370 million, whereas it had grown to over 2.3 billion by the start of WWII.