a continent in the northern hemisphere, separated from Africa on the south by the Mediterranean Sea and from Asia on the east roughly by the Bosporus, the Caucasus Mountains, and the Ural Mountains. Europe contains approximately 10 percent of the world's population. It consists of the western part of the landmass of which Asia forms the eastern (and greater) part and includes the British Isles, Iceland, and most of the Mediterranean islands. Its recent history has been dominated by the decline of European states from their former colonial and economic preeminence, the emergence of the European Union among the wealthy democracies of western Europe, and the collapse of the Soviet Union with consequent changes of power in central and eastern Europe.