1. WWI: Years of Deadlock

2. Stalemate By November 1914 the war had become a stalemate.
Stalemate: a deadlock, or situation in which neither side can budge the other.
On the Western Front, both sides build trenches and dug in for the long haul.

11. Attempts to Move
At the battle of Ypres, the Germans introduced poison gas a weapon.
At the battle of Verdun, the Germans attacked. Both sides lost 500,000 men and no ground changed hands.

14. New Weapons
At the Battle of the Somme the British introduced the tank.
At the Battle of the Somme, the British attacked. Once again both sides lost thousands of men and no land changed hands.