(Bonus) WWI: Trench Warfare

(Bonus) Trench warfare is a type of land warfare using occupied fighting lines largely comprising military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. Trench warfare became archetypically associated with World War I (1914–1918), when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914. Trench warfare proliferated when a revolution in firepower was not matched by similar
advances in mobility, resulting in a gruelling form of warfare in which the defender held
the advantage. On the Western Front in 1914–1918, both sides constructed elaborate
trench, underground, and dugout systems opposing each other along a front, protected
from assault by barbed wire. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.
The development of armored warfare and combined arms tactics permitted static lines to be bypassed and defeated, leading to the decline of trench warfare after the war.