The chain of events leading immediately to World War I began with the Ottoman Empire's defeat by imperialistic Italy in 1911–1912 and its resulting loss of Libya in North Africa and of the Greek-speaking Dodecanese Islands in the Aegean. On June 28, 1914, at Sarajevo, the capital city of Bosnia, the heir to the imperial throne of Austria-Hungary was assassinated by a fanatical young Serb nationalist. The government at Vienna dispatched an ultimatum to Belgrade, accusing Serbia of complicity in the crime and demanding acceptance of the Empire's control of nationalist propaganda and conduct from within Serbia. The Paris Peace Congress of 1919–1920, unlike the Vienna Congress of 1815, recognized the principle of nationality and wrote it into the public law of Europe. Four great imperial domains were dismembered—the Dual Monarchy of Austria-Hungary, the Ottoman Empire, the Russian Empire, the German Empire.