What followed? First, the Dutch, having built up a shipping industry, so to speak, on the backbone of the herring, were able to get the trade of distributing these goods from Lisbon to the north European countries. This, in turn, caused competition on the part of the English, who were not intending to be left out of the new fortune. Secondly, the Dutch and English began themselves to voyage to the East. And thirdly, the discovery of the rich possibilities of the East and West not merely made the Mediterranean commercially of little future account, but gave to the nations of the European Atlantic coasts an impetus to progress and a reason for strife which had never yet occurred. The history of the seventeenth to the twentieth centuries is confined to the struggle for the dominion of the seas—that is, maritime commercial supremacy, caused by the flow of trade taking a new route. The wars with the Dutch, the French and the Spanish were at heart the struggle for possession of overseas commerce, and the recent war with Germany was animated by the same cause. It is impossible to emphasise this trade route influence too much, for without a clear appreciation of its place in history the sequence of events becomes meaningless, and the rise and development of the Mercantile Marine seem arbitrary. Prince Henry the Navigator started a wonderful sea contest, and it has never stopped during the ensuing centuries. As soon as one keen competitor drops out, another comes in to keep up the running. That has been the impelling influence in the history of the English Mercantile Marine. When Spain falls out, the Dutch take her place. When they cease to be competitors, the French become the pacemakers, to be followed by the Germans; and now that the latter have disappeared almost entirely from the sea, the United States ships of commerce will maintain this ancient contest. And so it will go on, unless air routes cause another revolution in the transport of merchandise, and give another sudden twist to the flow of history.