The Balkans are often referred to as the "Powder keg of Europe" because the area saw a number of smaller events that eventually set off much larger ones, leading to World War I. The area is also sometimes called the "Balkan Powder Keg" and refers specifically to the early 20th century before World War I.
Although the term specifically refers to tensions within the Balkan region, it also resembles the volatile dynamics within Europe during the time period. The time period featured many intertwining claims to territories and spheres of influence among key parts of Europe such as Austria-Hungary, Russia, Imperial Germany, and Italy, the Ottoman Empire and Great Britain to a lesser extent. The Balkan region includes southeastern Europe, with countries that include Albania, Serbia, Greece, Bulgaria and Yugoslavia. The Balkan states were under control of the Ottoman Empire for centuries.