The European wars of religion were proportionately as destructive as, probably more destructive than, World War I.

Judged as of 2012-11. The claim is hedged ('probably more'). True: standard estimates show that the European wars of religion (e.g. Thirty Years' War, French Wars of Religion) killed a share of the relevant population equal to or greater than World War I's share (roughly 1–2% of world population or ~5–10% of the populations of countries involved), on a comparable basis. Mostly true: they were at least about as destructive proportionately, but estimates suggest they were not clearly more so. Mixed: estimates differ widely, with some showing them more destructive and others clearly less. Mostly false: on common estimates they were proportionately clearly less destructive than WWI, though one war (e.g. the Thirty Years' War in German lands) was locally comparable. False: estimates show them clearly and consistently less destructive proportionately than World War I.

Set before the research began.

1. E1 European wars of religion - Wikipedia Wikipedia

   “The conflicts culminated in the Thirty Years' War, which devastated Germany and killed one third of its population.”

2. E2 French Wars of Religion - Wikipedia Wikipedia

   “Between two and four million people died from violence, famine or disease directly caused by the conflict, and it severely damaged the power of the French monarchy.”

3. E3 How many people were killed during the French Wars of Religion? Social history in the Touraine ~ Central France (Jim McNeill blog) · 12 September 2012

   “Deaths during the wars estimated at 2,000,000 to 4,000,000.”

4. E4 Germany - Thirty Years War, Westphalia, Peace Encyclopædia Britannica

   “in 1631, imperial troops massacred two-thirds of the population of Magdeburg, a city of 20,000 that had withstood a long siege.”

E1 says the Thirty Years' War, the culminating war of the European wars of religion, killed one third of Germany's population. That is far above the benchmark the criteria give for World War I, about 5–10% of the populations of the countries involved. E2 and E3 put deaths in the French Wars of Religion at 2–4 million, but neither gives a population base, so no proportional comparison can be made for that conflict. The evidence supports the claim for the Thirty Years' War in Germany, which it says killed one third of the population [E1], but it gives no comparable population share for the wars of religion as a whole, so the verdict is mostly true rather than fully true.