The Guns of August Addressed is prewar military planning, as done by the major powers in Europe. Included are the German Schlieffen plan, France's offensive Plan XVII, joint British and French arrangements, and Russia's approach to a future European war. "Outbreak" starts with a short introduction, which briefly mentions the event that triggered World War I. On June 28, 1914, in Sarajevo, Gavrilo Princip, a Serbian nationalist, assassinated the heir apparent to the throne of Austria-Hungary, the Archduke Franz Ferdinand and his wife Sophie, Duchess of Hohenberg. European-wide diplomacy and military preparations during July are then referenced. Chapters 6 to 9 commence with August
Archduke Otto of Austria (1865–1906) of Emperor Franz Joseph I of Austria; and Karl Ludwig became heir presumptive to the Austro-Hungarian throne when his nephew Crown Prince Rudolf died in 1889. Although a newspaper account claimed that Karl Ludwig renounced his rights to the throne that same year (1889) in favour of his eldest son, Franz Ferdinand, that story is not certain. On the death of Karl Ludwig in May 1896, Otto's brother Franz Ferdinand did indeed become heir presumptive to the Austro-Hungarian throne. At the time of their father's death, Franz Ferdinand had been ill with tuberculosis and there was speculation that Franz Ferdinand