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.
Never before had a war been so global in scope. Prior to the outbreak of war in 1914, Europe had experienced a period of relative peace and prosperity. There is a great book, called 1913: In Search of the World Before the Great War, that highlights the pleasant culture of pre-World War I Europe.