where this range opens two passes of only 1,800 feet elevation to the upper Po Valley, made an active maritime town of Genoa from Strabo’s day to the present.  In its incipiency it relied upon one mediocre harbor on an otherwise harborless coast, a local supply of timber for its ships, and a road northward across the mountains.[523] The maritime ascendency in the Middle Ages of Genoa, Pisa, Venice, and Barcelona proves that no long indented coast is necessary, but only one tolerable harbor coupled with an advantageous location.

[Sidenote:  Intermediate location between contrasted coasts.]

Owing to the ease and cheapness of water transportation, a seaboard position between two other coasts of contrasted products due to a difference either of zonal location or of economic development or of both combined, insures commercial exchanges and the inevitable activities of the middleman.  The position of Carthage near the center of the Mediterranean enabled her to fatten on the trade between the highly developed eastern basin and the retarded western one.  Midway between the teeming industrial towns of medieval Flanders, Holland, and western Germany, and the new unexploited districts of retarded Russia, Poland, and Scandinavia, lay the long line of the German Hanseatic towns—­Kiel, Lubeck, Wiemar, Rostock, Stralsund, Greifswald, Anclam, Stettin, and Colberg, the civitates maritimae.  For three centuries or more they made themselves the dominant commercial and maritime power of the Baltic by exchanging Flemish fabrics, German hardware, and Spanish wines for the furs and wax of Russian forests, tallow and hides from Polish pastures, and crude metals from Swedish mines.[524] So Portugal by its geographical location became a staple place where the tropical products from the East Indies were transferred to the vessels of Dutch merchants, and by them distributed to northern Europe.  Later New England, by a parallel location, became the middleman in the exchanges of the tropical products of the West Indies, the tobacco of Virginia, and the wheat of Maryland for the manufactured wares of England and the fish of Newfoundland.

[Sidenote:  Historical decline of certain coasts.]

Primitive or early maritime commerce has always been characterized by the short beat, a succession of middlemen coasts, and a close series of staple-places, such as served the early Indian Ocean trade in Oman, Malabar Coast, Ceylon, Coromandel Coast, Malacca, and Java.  Therefore, many a littoral admirably situated for middleman trade loses this advantage so soon as commerce matures enough to extend the sweep of its voyages, and to bring into direct contact the two nations for which that coast was intermediary.  This is only another aspect of the anthropo-geographic evolution from small to large areas.  The decline of the Mediterranean coasts followed close upon the discovery of the sea-route to India; nor was their local importance restored by the Suez Canal.  Portugal declined when the Dutch, excluded from the Tagus mouth on the union of Portugal with Spain, found their way to the Spice Isles.  Ceylon, though still the chief port of call in the Indian Ocean, has lost its preeminence as chief market for all the lands between Africa and China, which it enjoyed in the sixth century, owing to the “long haul” of modern oceanic commerce.