The League made war on the pirates and did much to reduce the dangers of traffic. Instead of dispatching separate and defenseless merchantmen, their ships sailed out in fleets under the protection of a man-of-war. On one occasion the League undertook a successful war against the king of Denmark, who had interfered with their interests. At another time it declared war on England and brought her to terms. For two hundred years before the discovery of America, the League played a great part in the commercial affairs of western Europe; but it had begun to decline even before the discovery of new routes to the East and West Indies revolutionized trade. [Sidenote: Trade regulated by the towns (thirteenth to fifteenth century), not by nations or individuals.] It should be observed that, during the thirteenth, fourteenth, and fifteenth centuries, trade was not carried on between nations, but by the various towns, like Venice, Lübeck, Ghent, Bruges, Cologne. A merchant did not act or trade as an independent individual but as a member of a particular merchant guild, and he enjoyed the protection of his town and of the treaties it arranged. If a merchant from a certain town failed to pay a debt, a fellow-townsman might be seized where the debt was due. At the period of which we have been speaking, an inhabitant of London was considered a foreigner or an alien in Bristol, just as was the merchant from Cologne or Antwerp. Only gradually did the towns merge into the nations to which their people belonged.[158] [Sidenote: The burghers, or commons, become an influential class.] The increasing wealth of the merchants could not fail to raise them to a position of importance in society which they had not hitherto enjoyed. Their prosperity enabled them to vie with the clergy in education and with the nobility in the luxury of their dwellings and surroundings. They began to give some attention to reading, and as early as the fourteenth century many of the books appear to have been written with a view of meeting their tastes and needs. Representatives of the towns were called into the councils of the king, who was obliged to take their advice along with their contributions to the support of the government. The rise of the burgher class alongside the older orders of the clergy and nobility, which had so long dominated the life of western Europe, is one of the most momentous changes of the thirteenth century.