Trenches were widespread on the Western Front - a 400-plus mile stretch weaving through France and Belgium and down to the Swiss border. This is where the majority of British and Irish soldiers ...

By the spring of 1915, the German army had swept through most of neutral Belgium and Canadian troops ... chlorine gas - rose from the German trenches and moved slowly with the wind over the ...

The German northern wing was weakened further by the removal of 11 divisions to fight in Belgium and East Prussia ... Allied attacks from the shelter of trenches: the First Battle of the Aisne ...