- Russo-Japanese War: The Russo-Japanese War begins on February 8, 1904, when the Imperial Japanese Navy launches a surprise attack on the Russian fleet at Port Arthur. The war lasts until September 5, 1905, and results in a Japanese victory.
- Entente Cordiale: On April 8, 1904, the United Kingdom and France sign the Entente Cordiale, an agreement that resolves several colonial disputes and marks the beginning of a close diplomatic relationship between the two countries.
- Algeciras Conference: In January 1906, the Algeciras Conference is held in Spain to discuss the status of Morocco. The conference results in a Franco-Spanish agreement that gives France control over most of Morocco.
1908
- Austrian Annexation of Bosnia and Herzegovina: On October 6, 1908, Austria-Hungary annexes Bosnia and Herzegovina, two provinces of the Ottoman Empire that it had occupied since 1878. The annexation causes widespread outrage in Serbia, which sees it as a violation of Serbian national interests.
- Young Turk Revolution: In July 1908, the Young Turk Revolution begins in the Ottoman Empire. The revolution is led by a group of young officers who are unhappy with the corruption and inefficiency of the Ottoman government. The Young Turks succeed in overthrowing Sultan Abdul Hamid II and replacing him with a new government that promises to reform the empire.
- First Balkan War: The First Balkan War begins in October 1912, when the Balkan League, an alliance of Serbia, Bulgaria, Greece, and Montenegro, declares war on the Ottoman Empire. The war ends in May 1913, with a decisive victory for the Balkan League.