theworldwar.org

KYv5a TIL World War I trenches were constructed of sandbags, planks of wood, plaited wicker, tangled barbed wire, or even just mud. The trench systems on the Western Front were about 475 miles long, extending from the English Channel to the Swiss Alps, though not in a continuous line.
DQElg TIL that when French forces led by King Francis I attacked Arles in southern France in 1536, the word "grenade" was first used. Firepots, kegs, jars, and glass globes were used to make the first grenades. The Germans quickly began using two grenade variants (stick and egg).