The Great Slaughter
By 1916, the trenches on the Western Front had become elaborate systems of defence. Barbed wire, machine-gun nests, and heavy artillery protected the trenches on both sides. The troops lived in holes in the ground. A strip of land, known as no- man’s-land, separated the opposing forces. The leaders believed that if they could break through enemy lines, they could return to the type of fighting that they understood. World War I had turned into a war of attrition, a war based on wearing the other side down by constant attacks and heavy losses.
For the first time in history, airplanes appeared over battlefields in 1915. The Germans also used their giant airships, the zeppelins, to bomb London and eastern England. The zeppelins were filled with hydrogen gas