The Balkans as a cause of World War I


A map of the Balkans in 1914, showing recent territorial changes and the extent of Ottoman rule

A good deal of the European tension prior to World War I was derived from incidents and events in the Balkans. This large eastern European peninsula was sandwiched between four seas (the Mediterranean, the Black Sea, the Adriatic and Aegean) and three great empires (Russia, Austria-Hungary and the Ottomans). The Balkan peninsula was occupied by a jigsaw of nations and provinces including Greece, Serbia, Bulgaria, Macedonia and Bosnia. In the early 20th century the Balkan region was less populated and much less developed than the industrial powers of western Europe. Balkan economies were chiefly agricultural and the region had few natural resources, so it not considered to be of economic importance. Of greater significance was the region’s geographic location. The Balkans served as both a land and maritime junction between the Ottoman, Russian and Austro-Hungarian empires. Access to parts of the Balkans also meant access to several major waterways, making it strategically important for nations with a sizeable naval presence in the region. Because of these factors the Balkans were for centuries a gateway between East and West, an area of cultural and mercantile exchange, and a melting pot of ethnicities and people. But the peninsula was also politically unstable and volatile. The Balkans housed a cluster of governments, nationalist movements and factions motivated by ethnicity, culture and self interest. It was also a breeding ground for illegal separatist and terrorist groups, which challenged the authority of existing governments and the influence of imperial powers like the Ottomans and Austria-Hungary.

The Balkan wars

The Balkans had undergone significant change and disorder during the late 19th century. At its peak the Ottoman Empire ruled most of eastern Europe, including the Balkan states. But by the late 1800s the weakening Ottoman Empire was in retreat, freeing up the Balkans for self-rule. In the late 19th century Greece, Serbia, Montenegro and Bulgaria all achieved independence from Ottoman rule. Western European powers – particularly Britain, France, Germany and Russia – developed a strong interest in the region, concerned about what might happen if the Ottoman Empire disintegrated. They referred to this dilemma as the ‘Eastern question’ and each developed their own foreign policy objectives. Russia, which had imperialist ambitions in eastern Europe, hoped to expand its territory into the Balkans and other areas formerly under Ottoman rule. The Russian navy, which had ports and vessels on the Black Sea, wanted control of the Bosphorus, a strategically important strait of water that connected the Black Sea with the Mediterranean. Britain was opposed to Russian expansion into the Mediterranean and the Middle East; as a consequence London wanted to hold together the Ottoman Empire for as long as possible, to provide a buffer against Russian expansion. Germany hoped to acquire bankrupt Ottoman regions as vassal states or possibly even as colonies.

“The region’s rising nationalist tensions and dizzying ethnic diversity confounded all attempts to find lasting solutions to the seemingly endless conflicts… European diplomats understood that ethnic, economic and political connections between Balkan groups and several of the Great Powers meant that a conflict in this region could easily expand… Few Europeans expected [the assassination of Franz Ferdinand] to lead to a large war, although another Balkan war was a distinct possibility… Most Europeans expected diplomacy and cooler heads to prevail, as they had so often in the recent past.”
Michael S. Neiberg, historian

In 1912 several Balkan nations, incited by Russia, signed a series of military alliances that formed the so-called Balkan League. The agenda of this coalition was to wage war on the Ottomans and drive them out of eastern Europe entirely. The League declared war in October 1912 and despite the looseness of their alliance, the Balkan states emerged victorious after just eight months of fighting. In June 1913 Bulgaria launched a surprise attack on its former Balkan League allies, in what was little more than an opportunistic grab for territory. The Bulgarians were quickly defeated by the Greeks, Serbians and Romanians in barely a month. The Treaty of Bucharest (August 1913) penalised Bulgaria severely, leaving it frustrated and hostile towards its neighbours. The Serbs, victorious in both Balkan Wars, were the main beneficiary; their nation almost doubled in size with the acquisition of Kosovo and parts of Macedonia and Albania. The two Balkan wars forced the Great Powers to revisit their foreign policy in the region – especially Russia, which was now dependent on Serbia as a buffer against Austro-Hungarian aggression.

Rising nationalism


A depiction of European powers hovering over the small but dangerous Balkan states

Serbia’s territorial gains had two significant outcomes, both of which contributed to the outbreak of World War I. The first was a sharp increase in Serbian nationalism. Several Serb nationalist groups had formed in the early 1900s and flourished for the next decade. Their primary aim was to free Serbia from foreign control and influence, particularly from Vienna. In 1908 the Austro-Hungarians formally annexed Bosnia and Herzegovina. This roused nationalist movements in the region. Groups like the Narodna Odbrana (‘People’s Defence’), Cma Ruka (‘Black Hand’) and Mlada Bosna (‘Young Bosnia’) all formed between 1908-1911 and pledged to drive out the Austro-Hungarians. These groups were encouraged by Russian agents, as well as individuals in the Serbian government, public service and military. Most of their activities revolved around political agitation or the production of anti-Austrian propaganda – but some also trained for and plotted acts of terrorism. Their most telling act was the killing of Archduke Franz Ferdinand in Sarajevo in June 1914, by a teenaged member of Cma Ruka, Gavrilo Princip. Another profound consequence of Serbian expansion was that it threatened the stability of Austro-Hungary. The Hapsburg empire had already surrendered significant territory to the Italians and the Russians in the 1870s; the developments in the Balkans in 1912-13 seemed to hint at even more losses. Austro-Hungarian generals began talking tough about Serbia. While the dual monarchy’s military strength and equipment lagged behind those of Germany, they believed it could easily vanquish the troublesome Serbs. The ageing Austrian emperor, Franz Josef, was not keen on war and was reluctant to place his cherished military at risk. But the assassination of his nephew and his heir, along with the ‘blank cheque’ offered by the German kaiser, roused the old man to action. Otto von Bismarck’s 1888 prediction about a future European war – that it would “start with some damn foolish thing in the Balkans” – was about to be proved correct.




1. The Balkans were a cluster of nations in eastern Europe, between the Austro-Hungarian and Ottoman empires.
2. Their location made the Balkans strategically important, so European powers were focused on events there.
3. The Balkans were also politically volatile, a hotbed of ethnic and nationalist tensions.
4. The Balkans were disrupted by two wars in 1912-13, as well as rising Serbian nationalist groups.
5. The assassination of Archduke Franz Ferdinand in the Balkan city of Sarajevo provided the Austro-Hungarian government with a pretext for crushing Serbian nationalism, something it had long desired.

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