The almost unbroken mountain chain formed by the Pyrenees, the Alps, and the Balkans, sharply separates the central land mass of Europe from the regions to the south. Central Europe consists, in general, of lowlands, which widen eastward into the vast Russian plain. Northern Europe includes the British Isles, physically an extension of Europe, and the peninsulas of Scandinavia and Finland, between the Baltic Sea and the Arctic Ocean. Twenty centuries ago central and northern Europe was a land of forests and marshes, of desolate steppes and icebound hills. The peoples who inhabited it--Celts in the west, Teutons or Germans in the north, Slavs in the east --were men of Indo-European [2] race and speech. They were still barbarians. During ancient times we hear little of them, except as their occasional migrations southward brought them into contact with the Greeks and the Romans. SOUTHERN EUROPE Southern Europe comprises the three peninsulas of Spain, Italy, and the Balkans, which reach far south into the Mediterranean. This great inland sea is divided into two parts near the center, where Africa and the island of Sicily almost touch each other across a narrow strait. The eastern part contains several minor seas, of which the one called the Aegean had most importance in Greek history. 21. GREECE AND THE AEGEAN THE AEGEAN SEA The Aegean is an almost landlocked body of water. The Balkan peninsula, narrowing toward the Mediterranean into the smaller peninsula of Greece, confines it on the west. On the east it meets a boundary in Asia Minor. The southern boundary is formed by a chain of islands, while the only opening northward is found in the narrow passage leading to the Black Sea. The coasts and islands of the Aegean thus make up a little world set off by itself. [Illustration: Map, PHYSICAL MAP OF EUROPE] CONTINENTAL GREECE Continental Greece is a tiny country. Its greatest length is scarcely more than two hundred and fifty miles; its greatest breadth is only one hundred and eighty miles. Mountain ridges, offshoots of the Balkans, compose the greater part of its area. Into the valleys and deep gorges of the interior the impetuous sea has everywhere forced a channel. The coast line, accordingly, is most irregular--a constant succession of sharp promontories and curving bays. The mountains, crossing the peninsula in confused masses, break it up into numberless valleys and glens which seldom widen into plains. The rivers are not navigable. The few lakes, hemmed in by the hills, have no outlets except in underground channels. In this land of the Greeks no place is more than fifty miles from a mountain range, or more than forty miles from some long arm of the Mediterranean. THE AEGEAN ISLANDS