A Russian adjustable mobile shield captured by the Germans, 1914

The immobility of trench warfare that characterized World War I led to the need for a device that would protect soldiers from enemy fire and help them move through the highly irregular terrain of battlefields.

Apart from a few exceptional cases, these mobile personnel shields proved too cumbersome and heavy for the strength of a person under fire, and would operate only over short ranges and on friendly ground.

The primary killer on the battlefields of the Great War was artillery, not rifles or machine guns. When the men carry their shields to protect them from rifle and machine-gun fire, a shell explodes on their heads and their brains are cut with shrapnel.

The original caption on the photo read: "Possessed Russian embrasures, which are mobile and can be moved and changed displacement". To stop the high-power rifle rounds, they needed heavyweight steel plates. This made it difficult for them to walk and be carried (usually by horses).