How readily the peninsula affords easy access between Europe and Asia can be gathered from the map. The narrow watercourse which begins at the Ægean mouth of the Dardanelles and extends to the Black Sea entrance of the Bosporus provides, at both its extremities, the shortest fording places between the two continents. At Chanak, on the Dardanelles, about one mile and a half of channel separates the peninsula of Gallipoli from the Anatolian coast. The very outline of the European shore is symbolical, for in the Thracian and Gallipoli promontories the Balkan peninsula seems to stretch out two welcoming arms to Asia and thus invite intercourse. South of the straits, the deeply indented coast lines of Greece and of Asia Minor teemed with matchless harbors. Their shores became the birthplace of adventurous sailors. The Ægean itself, with its numerous islands, provided so many stepping-stones jutting out of its choppy waters to aid daring pioneers in their expeditions. Every race of Europe and of western Asia has marched at some time or other through the valleys that extend in varying width between the uplifts rising south of the Danube and the Save. The attempt to determine the original element is almost futile in the face of the constant stream of invaders. To go back only to the period following the one in which the Thracians dotted the southeastern area with their quaint tumuli we find the peninsula already settled by Illyrians on its western border. The Albanians are supposed to be direct descendants of this ancient people. Secluded in their mountain fastnesses from contact with subsequent invaders of the peninsula, they best represent today the type of the peninsular inhabitant of about 2000 B.C. To the east the basin of the Danube was peopled subsequently by Dacians and Gaetes, who presumably were the ancestors of the peasants now occupying the Dobrudja. North of the boundary-defining rivers dwelt the Scythians and the Sarmatians. The story of their migrations is the same for different epochs. It tells either of the appearance of sturdy barbarians before whose dash the settlers, somewhat effete on account of acquired comfort, give way. Or else it is the tale of the settler who has had time to organize his forces into orderly fighters and whose disciplined bands go forth to conquer new territory at the behest of his civilization. Thus did Roman legions sweep away the barriers to the acquisition of new colonies.