Irish citizens campaign against conscription by the British Government, 1918
World War I broke out on 28 July 1914, pitting an alliance spearheaded by Germany and Austria-Hungary against the forces of the United Kingdom (UK), France, Russia, and their allies. Due to paradigm shifts in military technology, the war quickly turned continental Europe into a charnel house. Nations soon found themselves requiring more manpower than ever before to maintain their war efforts.