The July Crisis

The July Crisis is the name given to a period of diplomatic maneuvering and military planning among the Great Powers of Europe in the early summer of 1914, culminating in the outbreak of World War I. It began on June 28, with the assassination of Archduke Franz Ferdinand in Sarajevo, Bosnia, and is normally considered to have ended on August 4, with Great Britain's declaration of war on Germany. After this date, the Triple Entente of Britain, France, and Russia were formally in hostilities with the Central Powers, Germany and Austria-Hungary, with other combatants later joining on both sides.

The crisis was sparked by Austria-Hungary's determination to punish Serbia, which it believed to be behind the assassination of the archduke, which triggered the alliance systems and war plans of the other powers. The degree to which any one power was especially responsible for this chain of events has been hotly debated among historians and politicians since 1914, though Germany is most often singled out for culpability. Because of its results, including the war itself and the later aftermath of that conflict, the crisis is widely regarded as one of the most significant periods in 20th-century European and even world history.