The Balkan Peninsula... by the early 20th century, the Ottoman Empire was in steep decline. This decline fueled nationalist movements in the Balkans, where various ethnic groups sought independence or territorial expansion. Countries like Serbia, Greece, Bulgaria, and Montenegro, which had gained independence or autonomy in the previous century, aspired to expand their territories further, often at the expense of their neighbors and the Ottoman Empire. These aspirations were driven by both nationalistic fervor and the desire to control strategic territories like Macedonia, a region with a highly diverse population. In response to these growing tensions, the Balkan League—a coalition...