Imperial Europe (4 January 1894)
Historical Map of Europe & the Mediterranean
German attempts to keep France isolated by maintaining alliances with the other powers of Europe began to unravel in the late 1880s when Russia broke with the League of Three Emperors over conflicting interests with Austria-Hungary. In 1894, the Russians went a step further and joined in a formal alliance with the French. There were now two opposing power blocs in Europe.
Unification of Bulgaria
In late 1885, the nationalistic Bulgarian Secret Central Revolutionary Committee (BSCRC) led a series of uprisings in Eastern Rumelia in favor of union with the northern Principality of Bulgaria. The revolt culminated on 18 September [6 September O.S.] 1885, when the rebels took over the Eastern Rumelian government in Plovdiv and proclaimed Bulgarian unification. The Principality of Bulgaria obliged four days later, annexing Eastern Rumelia as South Bulgaria.
The unification of Bulgaria was not recognized by the Great Powers and strongly opposed by Serbia, who saw the large new state as a threat. Under the promise of protection by Austria-Hungary, Serbia attacked Bulgaria but was defeated in just two weeks, leading the Great Powers to recognize Bulgarian unification.
End of the League of Three Emperors
By 1887, the decline of Ottoman power in the Balkans had made Russia and Austria-Hungary into rivals, while the rising militarization of Germany directly threatened Russia. This disincentivized Russia from renewing the League of the Three Emperors, causing the alliance to end.
Downfall of Otto von Bismarck
In 1888, Kaiser Wilhelm II acceded the German throne. Unhappy with Chancellor Bismarck's moderate foreign policy, Wilhelm dismissed him.
In order to settle ownership of the East African island of Zanzibar, Germany ceded its claim to Britain in exchange for Britain's cession of the Heligoland archipelago.
Accession of Adolphe of Luxembourg
On 23 November 1890, King William III of the Netherlands died. Rule over the Netherlands passed to his only child, Queen Wilhelmina, who was barred by semi-Salic law from also serving as Grand Duchess of Luxembourg. Therefore, the Luxembourgish throne passed to William's father-in-law Adolphe, the former Duke of Nassau.
Fearful of the rapidly growing military power of the German Empire, France and Russia formed an alliance to aid each other in the event of a German attack.