First Balkan War: The Ottomans lose the cities of Thessaloniki and Skopje.

First Balkan War

1912–1913 war between the Balkan League and the Ottoman Empire

The First Balkan War lasted from October 1912 to May 1913 and involved actions of the Balkan League against the Ottoman Empire. The Balkan states' combined armies overcame the initially numerically inferior and strategically disadvantaged Ottoman armies, achieving rapid success.