28 June — in Sarajevo (Bosnia), Austrian Archduke Franz Ferdinand was assassinated. The attempt on the archduke was carried out by the clandestine group “Young Bosnia” (“Mlada Bosna”), which fought for the unification of all South Slavic peoples into a single state and was led by Gavrilo Princip and Danilo Ilic. This fact in itself did not threaten world peace. The world press initially assessed it relatively calmly, and the public reacted with indifference. The response in diplomatic circles was restrained. However, the ruling circles of Austria and Germany decided to use the Sarajevo assassination as a pretext for war.
5 July — Germany promises support to Austria-Hungary in the event of a conflict with Serbia.
23 July — Austria-Hungary, claiming that Serbia was behind the assassination of Franz Ferdinand, issues an ultimatum demanding that Serbia comply with deliberately unacceptable conditions. These included purging the state apparatus and the army of officers and officials suspected of anti-Austrian propaganda; arresting those suspected of aiding terrorism; and allowing Austria-Hungary’s police to conduct investigations on Serbian territory and punish those responsible for anti-Austrian actions. Only 48 hours were given for a reply.
On the same day, Serbia begins mobilization; however, it agrees to all of Austria-Hungary’s demands except allowing Austrian police onto its territory. Germany persistently pushes Austria-Hungary to declare war on Serbia.
25 July — Germany begins a covert mobilization.
26 July — Austria-Hungary declares general mobilization and begins concentrating troops on the border with Serbia and Russia.
28 July — Austria-Hungary, stating that the ultimatum’s demands have not been met, declares war on Serbia. Russia states that it will not allow the occupation of Serbia.
30 July — mobilization begins in France.
31 July — general mobilization into the army is declared in Russia.
On the same day, Germany presents Russia with an ultimatum: stop the call-up to the army, or Germany will declare war on Russia. France, Austria-Hungary, and Germany carry out mobilization. Germany moves troops toward the Belgian and French borders...
Thus, the assassination of Archduke Ferdinand served as the повод for the start of World War I, which involved 38 independent states. As a result of the war, four empires ceased to exist: the Russian, German, Austro-Hungarian, and Ottoman Empires. About 74 million people were mobilized; the participating countries lost about 10 million killed, and 22 million were wounded.
After Ferdinand’s assassination, “Young Bosnia” was banned. Ilic and two other participants in the attempt were executed. Gavrilo Princip, convicted as a minor, was sentenced to 20 years of hard labor and died of tuberculosis in prison. Other members of the organization received various prison terms.