| YEAR | MONTH | EVENT |
| 1871 | January 18 | William I of Prussia becomes emperor of united Germany. |
| | May 10 | Peace of Frankfurt ends Franco-Prussian War; France loses eastern provinces of Alsace and Lorraine to Germany. |
| 1872 | | Germany, Austria, and Russia form "League of Three Emperors" against France. |
| 1875 | | Bosnia-Herzegovina rebels against Ottoman Empire. |
| 1877 | January | Russo-Turkish War begins; Russia supports Balkan Slav Christians in Ottoman Empire (Eastern Question), seeking land, influence, and prestige. |
| 1878 | March | Russo-Turkish War ends with Treaty of San Stefano. |
| | June-July | Congress of Berlin with German Chancellor Otto von Bismarck as " honest broker"; Romania, Serbia, and Montenegro freed from Ottoman Empire, Bulgaria divided and partly independent; Austro-Hungarian Empire gains administrative rights over Bosnia-Herzegovina; tensions in Balkans grow. |
| 1879 | | Dual Alliance of Germany and Austro-Hungarian Empire. |
| 1882 | May | Triple Alliance of Germany, Austro-Hungarian Empire, and Italy. |
| 1885 | | Bulgaria takes Eastern Rumelia from Ottoman Empire; Bismarck uses Italy, Great Britain, and Austro-Hungarian Empire to prevent Russian interference. |
| 1887 | | Rivalry of Russia and Austro-Hungarian Empire over Balkans ends "League of Three Emperors". |
| | June 18 | Secret Reinsurance Treaty reaffirms Russo-German alliance. |
| 1888 | June | William II becomes emperor of Germany. |
| 1890 | March | William II dismisses Bismarck; German foreign policy shifts. William II cancels Russo-German Reinsurance Treaty against Russia's wishes, Austro-Hungarian Empire's position indirectly weakened, Germany faces encirclement. |
| 1894 | January | Dual Alliance of France and Russia against Triple Alliance finalized. Pan-German League formed to promote German expansion and proto-fascism. |
| 1896 | January | Kruger Telegram from William II praising Boers angers British. Archduke Francis Ferdinand becomes heir to Austro-Hungarian throne; his federalist aims make him target of Greater Serb nationalists seeking to dismantle Habsburg dominions. |
| 1897 | | Russia and Austro-Hungarian Empire agree to maintain Balkan status quo for 10 years. Dreyfus Affair erupts in France over German spies in French army. |
| 1898 | | Fashoda Crisis between France and Great Britain over French presence in Sudan. Germany begins naval construction programme; start of naval arms race. Attempts to establish Anglo-German alliance fail. |
| 1899 | May | First Hague Conference convened; establishes international arbitration forum and limits on warfare. Renewal of Franco-Russian Dual Alliance. |
| 1900 | | Secret Franco-Italian agreement over African interests; Triple Alliance undermined, especially Austro-Hungarian Empire; Italy free to pursue Balkan goals. |
| 1902 | | Great Britain forms alliance with Japan. |
| 1904 | February | Russo-Japanese War begins. |
| | April | France and Britain conclude "Entente Cordiale", partly to avoid involvement in Russo-Japanese War. |
| 1905 | March | First Moroccan Crisis: William II backs Morocco against French. |
| | September | Treaty of Portsmouth ends Russo-Japanese War; arrival of Japan as world power; humiliated Russia turns back to Eastern Question. German General Staff finalize Schlieffen Plan for war on France and Russia. |
| 1906 | January-April | Algeciras conference averts war over Morocco. Britain launches Dreadnought battleship. |
| 1907 | June | Second Hague Conference convened, expands and clarifies rules of war; Germany rejects disarmament proposals, exacerbating mistrust. Triple Entente of France, Great Britain, and Russia; Anglo-Russian agreement removes British restraint on Russia's Balkan ambitions. |
| 1908 | July | Young Turk Revolution in Ottoman Empire initiates Balkan crisis. |
| | October | Austro-Hungarian Empire annexes Bosnia-Herzegovina, enraging Serbia; Russia angered but unwilling to back Serbian demands for war. William II's careless remarks in Daily Telegraph interview enrage British. |
| 1909 | March | Petersburg Dispatch from Austro-Hungarian Empire warning against Balkan involvement enrages Russia against Central Powers. Secret Russo-Italian Treaty of Racconigi to maintain Balkan status quo. |
| 1911 | July | Second Moroccan Crisis; German warship Panther sent to Agadir to challenge French interests. |
| | September | Italo-Turkish War begins; Triple Alliance undermined by strain on German friendship with Ottoman Empire. |
| | November | Agadir conference averts war; Morocco made French protectorate; Germany receives territorial compensation, but its isolation is demonstrated. Serbian Black Hand terrorist society advocating Greater Serbia formed. Germany grants Alsace and Lorraine limited autonomy. |
| 1912 | October | Treaty of Lausanne ends Italo-Turkish War; Italy gains Libya. First Balkan War; Balkan League attacks Ottoman Empire, and liberates Albania and Macedonia. Failure of Anglo-German naval limitation talks; arms race intensifies. |
| | December | William II's councillors advocate early war to break encirclement by Triple Entente. |
| 1913 | May | Treaty of London ends First Balkan War; Ottomans surrender Crete to Greece; Albania made independent; Macedonia partitioned; Serbia dissatisfied and forms anti-Bulgarian alliance with Greece. |
| | June-August | Second Balkan War; Bulgaria vanquished by hostile coalition; Austro-Hungarian Empire stops Serbia from seizing Adriatic Coast; Serbia doubles size, with Austrian Bosnia-Herzegovina its next objective. Preparations for war: Germany increases army; France lengthens conscription from two to three years; European powers increase military budgets. |
| 1914 | June 28 | Black Hand agents assassinate Francis Ferdinand in Sarajevo. |
| | July 6 | Germany assures Austro-Hungarian Empire of complete fidelity to alliance. |
| | July 20 | French president visits Russia, assures Russia of complete fidelity. |
| | July 23 | Austrian ultimatum to Serbia demanding prosecution of culprits. |
| | July 25 | Serbia accepts most ultimatum terms and partially mobilizes. Russia decides to support Serbia; British and German mediation offers rejected. |
| | July 28 | Austro-Hungarian Empire declares war on Serbia (to curb Serb/Slav threat). |
| | July 29 | Russia partially mobilizes. |
| | July 30 | Full Russian mobilization. |
| | July 31 | Full Austro-Hungarian mobilization; Germany issues ultimatums to Russia (suspension of mobilization) and France (neutrality)-no response. |
| | August 1 | Germany mobilizes and declares war on Russia; Great Britain mobilizes fleet. |
| | August 2 | Belgium refuses German demand to permit passage of troops to attack France; Britain guarantees French coastal security. |
| | August 3 | Germany declares war on France and invades Belgium; Italy declares neutrality. |
| | August 4 | British ultimatum to Germany to respect Belgian neutrality (effective declaration of war). |
| | August 6 | Serbia declares war on Germany; Austro-Hungarian Empire declares war on Russia. |
| | August 11 | France declares war on Austro-Hungarian Empire. |
| | August 12 | Great Britain declares war on Austro-Hungarian Empire. |
| | August 23 | Japan declares war on Germany. |
