Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. To the east and southeast, Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits.The period of European history extending from about 500 to 1400–1500 CE is traditionally known as the Middle Ages. The term was first used by 15th-century scholars to designate the period between their own time and the fall of the Western Roman Empire. The period is often considered to have its own internal divisions: either early and late or early, central or high, and late.