Serbia, as seen in the previous chapter, was an Austro-Hungarian satellite state until the overthrow of King Alexander in 1903. At that point, the new government shifted its loyalties to Russia and undertook policies aiming to create a Greater Serbia. The principal events touching Serbia in the years leading up to August 1914 were a trade war with Austria-Hungary (called the “Pig War”), the Young Turk revolt of July 1908, the Austro-Hungarian takeover of Bosnia-Herzegovina in October of that year, and finally the two Balkan Wars of 1912–13. The latter included also Bulgaria, Greece, Montenegro, and of course the Ottoman Empire. For the inhabitants of these Balkan states war began in October 1912, and lasted, with short breaks, until October 1918. The “Pig War,” which refers to Austria-Hungary's ban on a prominent item of Serbian commerce, ended Serbian economic dependence on Austria-Hungary. It also exacerbated tensions between the two neighbors. These tensions increased still further as a result of the Austro-Hungarian annexation of Bosnia-Herzegovina soon after the Young Turks' assumption of power in Constantinople. The Austrians feared that the reform program of the Young Turks might cause the loss of Bosnia-Herzegovina, an Ottoman province under Austrian occupation since 1878. The Serbs coveted Bosnia because the largest single national group in that province at that time was Serbian. They greatly resented the annexation.

In the two Balkan Wars of this period, the Serbs sought to enlarge their territories to include as many of their conationals as possible.