- First started on the Western front with little hope that it would become a useful tactic

- Started September 1914, near Chemin Des Dames Ridge

- Resulted in 475 miles of trench lines

- Ranged from North Sea to the Swiss border

- Never took place in the east because of distances and lack of manpower

- Eastern front instead worked on key points and improvised field fortifications

- Terrain ranged from swaps/mud plains, flat lands, forests, low hills, and industrial slay heaps

- Originally dug individual fighting holes but then linked them together to form the trenches