Why is the Balkans known as the "powder keg" of Europe?

The powder keg of europe is a diagrammatic illustration of European political alliances in the period leading up to the First World War. The "Powder keg of Europe ", sometimes alternately known as the " Balkan Powder Keg ", refers to the Balkans in the early part of the 20th century preceding World War I.

The Balkans, not a country specifically, but an area in southeastern Europe, have been the site of innumerable wars. Since the start of the 20th century this region was in a state of continuous upheaval starting with the First and Second Balkan Wars in 1912 and 1913 respectively. In 1914, Archduke Francis Ferdinand was assassinated in Sarajevo by a Serbian. His assassination sparked the beginning of World War I.

Because of this continual state of upheaval and the cultural, religious and ethnic mix, peace does not seem to be on the horizon for the Balkans.