World War I

Lore & Background

The causes of World War I included the rise of the German Empire, which disturbed the long-standing balance of power in Europe, and the exacerbation of imperial rivalries, reflected in new alliances and an arms race. Austria-Hungary blamed Serbia and declared war on 28 July, upon which the Russian Empire mobilised in Serbia's defence. In early August, Germany declared war on Russia and France; the United Kingdom entered the war after Germany invaded Belgium. The Eastern Front was more dynamic, but neither side gained a decisive advantage, despite costly offensives. The Ottoman Empire joined the Central Powers in November, followed by a failed Allied campaign at Gallipoli. Japan and Italy also joined the Allies.

Reader's Guide

World War I reshaped global politics and borders. Under the Treaty of Versailles, Germany lost significant territories, was disarmed, and was required to pay large war reparations to the Allies. The collapse of the Russian, German, Austro-Hungarian, and Ottoman empires resulted in new national boundaries and the creation of new independent states including Poland, Finland, the Baltic states, Czechoslovakia, and Yugoslavia. The war also saw major battles such as those at Verdun, the Somme, and Passchendaele, which failed to break the stalemate on the Western Front. In April 1917, the United States joined the Allies after Germany resumed unrestricted submarine warfare. Germany's spring offensive that year left its army exhausted, and the Allied Hundred Days Offensive caused a collapse of the German front line.

Did You Know?

• The war helped spread the Spanish flu pandemic.
• The conflict saw the first large-scale use of machine guns, artillery, aircraft, chemical weapons, and tanks.