At different periods the great commerce which flowed to and through this district chose different points for its concentration. In the fourteenth century the favored spot was Bruges (the Flemish word meaning bridges), the greatest market in northern Europe, vying even with Venice. Here could be found Scandinavians, Germans, English, French, Portuguese, Spaniards, and Italians, exchanging the wares from different sources; a contemporary writer names 30 different countries, both Christian and Mohammedan, which fed the market of Bruges with their commodities. The natives were content to let foreigners carry on the business of transportation; they stayed at home and grew rich from the wares, money and credit instruments which commerce brought to their doors. =124. Decline of Bruges in the fifteenth century; rise of Antwerp.=—Partly because of this passive part which they assumed, partly because of the practice of medieval countries in diverting their trade from one place to another, the people of Bruges had but a precarious hold on their commerce, and lost it in the fifteenth century. The silting up of its harbors, making these unfit to hold the larger ships now coming into use, explains in part the decline of Bruges, but political forces were at work also to divert commerce to another center. In the fifteenth century the place of Bruges as the great market of northern Europe was taken by Antwerp, which had fought its way up against all rivals, and which held the leadership now for one hundred years. =125. Conditions of commerce in England.=—England lay on the outside of the great currents of medieval commerce. It had an advantage which it had enjoyed since pre-Roman times, the practical monopoly of tin production in Europe; and added to this in the latter part of the Middle Ages a still more important monopoly, that of wool production. Sheep were raised, of course, in other parts of Europe, and the merinos of Spain yielded a finer grade of wool than could be produced in England. For some reason, however, the sheep industry did not prosper elsewhere as it did in England. Possibly the constant wars and raids which disturbed the feudal states of the continent may have prevented the production of a commodity which could be so easily destroyed or carried off as booty. At any rate, the more settled political conditions in England, where internal war became soon a rare exception, favored the development of all the national resources. Aided by the prevalence of peace at home, and by the disappearance of feudal tolls on trade, the English advanced rapidly in the fourteenth and fifteenth centuries and instead of exporting the raw wool began to make it into cloth and to export the finished product. Trade was furthered also by the continental conquests of English kings, which brought England and the South of France into close relationship, and built up a large import trade in French wines.