Some major events that occurred during World War I include the revolution in Russia, the Battle of Verdun and the sinking of the British luxury liner, Lusitania. All three events influenced the future of the war.
Germany's 1915 sinking of the British liner Lusitania changed public perception of the war in the United States. This event eventually led the United States to enter the war in 1917.
The Battle of Verdun in 1916, one of the longest of the war, stretched from February to December of that year. German and French troops had almost one million casualties combined during the battle.
In 1917, discontented with its inability to break through German lines, Russia fell into revolution as Vladimir Lenin led the Bolsheviks in overthrowing the Russian tsar.