First World War
First World war.com: The Third Battle of Ypres
Read through a detailed summary of a famous Canadian-led World War I battle, the Battle of Passchendaele. The site contains a wealth of primary sources including a progress map and links to biographies of important figures in the battle....
PBS
Pbs: The Battle of Passchendaele
PBS offers information on the third battle of Ypres. The battle is a case of weather affecting the outcome of a battle.