How many French died during World War 1?
About 1,700,000 French died during World War I, including soldiers and civilians.
Around 350,000 soldiers died which is incredible considering the brevity of the time France was in active war. (You should note however that the French people were actually very brave during the war and as a result around 500,000 citizens died during it! Around 10% of the French adult population was in the resistance despite the Germans bullying the French people to not help!)