The successive losses of factories and Hanseatic liberties in the kingdoms of the North and East, were of themselves a fatal shock to the prosperity of the League. It must be remembered that the great privileges attained by the League in times past in England, the Netherlands, France, and Spain, were all based on the monopoly acquired by them in trading in the products of Russia, Denmark, Sweden, and Norway. This monopoly, as we have seen in the last chapters, had been seriously threatened; factories had been forcibly closed, natives and strangers had competed with the Hanseatics; the League's prerogatives and charters had been trodden under foot and disregarded. All the efforts made by the Hanseatics at the end of the fifteenth century and in the early years of the sixteenth to expel from the Baltic waters their various competitors, had ended in failure. It obviously followed that, with the loss of this monopoly, the privileges extorted on the strength of it would vanish also; and this was speedily the case, for under what pretence of preference could the League now invoke special favours at the hands of the Eastern nations? These general causes of failure in the West were destined to be complicated in the case of the Netherlands with the adverse fate which befell the town of Bruges at the end of the second period of our story, and of which we have already spoken. The disaster which deprived the town of its commercial importance also contributed to ruin the Hanseatic factory established in that city. Then the Hanseatics themselves were not wholly blameless, seeing how at Bruges they repeatedly revolted against paying the tax enforced for storage of goods, a tax that was a regular condition in the statutes of the League, and which was exacted in all its foreign settlements; and, besides this, there are also other circumstances to be reckoned with, of a more general character. The closing of the factory of Bruges was one of many signs of the course of events. A new spirit was abroad affecting commerce and progress in all directions, a spirit against which, as we have said, the League resolutely set its face, and which it refused to recognize until it was too late. After the invasion of the territory of Bruges in 1488 and the ten years' blockade of the harbour of Sluys, by the Emperor Frederick III., to avenge the confinement of his son, the city found her trade almost ruined. Two important branches were lost to her, by the Italians who brought their own silk stuffs to the rival market of Antwerp and by the Flemish cloth-workers who had settled in England and likewise sent their goods thither.