A fleet carrier is intended to operate with the main fleet and usually provides an offensive capability. These are the largest carriers capable of fast speeds. By comparison, escort carriers were developed to provide defense for convoys of ships. They were smaller and slower with lower numbers of aircraft carried.
The First World War was sparked in the Balkans in 1914 when members of Mlada Bosna, a revolutionary organization with predominately Serbian and pro-Yugoslav members, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand of Austria in Bosnia and Herzegovina's capital, Sarajevo.
Europe was ready to blow. The tense, nationalistic feelings of the people in the Balkan region of the Austro-Hungarian Empire (Serbia, Bosnia, etc.) gave the region the nickname of the Powder Keg of Europe.. The spark that set the war off was the assassination of the heir to the Austrian Empire (Archduke Franz Ferdinand) by a Serbian national. Austria declared war on Serbia as a result.