How many people were in trenches during World War 1?

During World War I, millions of soldiers were stationed in trenches on the Western Front. At the height of the conflict, it is estimated that around 1 million troops could be in the trenches at any given time. The trench system was extensive, with both sides creating a network of front-line, support, and reserve trenches to accommodate their forces. The conditions were often overcrowded and unsanitary, leading to significant hardships for the soldiers.