Page "Trench warfare" Paragraph 15

Only with the advent of accurate firearms did the use of trenches as positions for the defender of a fortification become common.

Elaborate trench and bunker systems were employed by the Māori to withstand British artillery barrages, poison-gas shells and bayonet charges during the New Zealand Wars in the 1840s.

Trench systems were also employed in the Russo-Japanese War and American Civil War.

The military usage evolved very quickly in the First World War, until whole systems of extensive main trenches, backup trenches ( in case the first lines were overrun ) and communication trenches had been developed, often stretching dozens of kilometres along a front without interruption, and some kilometres further back from the opponent's lines.