The machine gun, which so came to dominate and even to personify the battlefields of World War One, was a fairly primitive device when general war began in August 1914. Machine guns of all armies were largely of the heavy variety and decidedly ill-suited to portability for use by rapidly advancing infantry troops. Each weighed somewhere in the 30kg-60kg range - often without their mountings, carriages and supplies.
When established in fixed strong-points sited specifically to cover potential enemy attack routes, the machine gun proved a fearsome defensive weapon. Enemy infantry assaults upon such positions invariably proved highly costly.
The British found, to their repeated cost, the futility of massed infantry attacks against well-entrenched defensive positions protected by machine gun cover. The first day of the Somme Offensive amply illustrated this, although the lesson appeared to be lost to the British high command. On the opening day of the offensive the British suffered a record number of single day casualties, 60,000, the great majority lost under withering machine gun fire.
Understandably most historical accounts of the First World War have tended to emphasize the defensive strengths of the machine gun. Throughout the war efforts were made to produce an infantry assault version, such as the Lewis Light Machine Gun (see right), although these efforts were generally unsatisfactory.
Although often not truly portable light machine guns were more readily transported on roads or flat ground by armored cars. As the war developed machine guns were adapted for use on tanks on broken ground, particularly on the Western Front (where the majority of machine guns were deployed).
Light machine guns were adopted too for incorporation into aircraft from 1915 onwards, for example the Vickers, particularly with the German adoption of interrupter equipment, which enabled the pilot to fire the gun through the aircraft's propeller blades.
In response to the increasing success of machine guns mounted on aircraft it was perhaps inevitable that machine guns should similarly be developed as anti-aircraft devices (in France and Italy), sometimes mounted on vehicles. Similarly machine guns began to be added to warships as a useful addition to naval armaments.