Trench warfare
Trench warfare occurred when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling 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, mines, camouflaged trapping pits, and other obstacles. 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.
Koos de la Rey
Having realised that the traditional Boer tactic of fighting from higher ground exposed them to the superior British artillery, de la Rey insisted that his men and Prinsloo's Free-Staters dig in on the banks of the Modder and Riet Rivers, the first use of trench warfare in the war. The plan was to hold fire until the British had approached close enough for the Boers' advantage in rifle fire to take effect, while making it difficult for the full force of the British artillery to be used. In the early hours the British troops advanced across the plain unopposed, but Prinsloo's men opened fire at long range, the troops took cover and the artillery pounded the Boer trenches. A series of British rushes pushed the Free-Staters back across the ford, and only a counter-attack led by de la Rey enabled the Boers to hold the field until dusk, when they slipped away. De la Rey was wounded and his son Adriaan was killed; he blamed Cronjé for failing to send reinforcements.