During the whole of the fourteenth and a considerable part of the fifteenth century these two guilds continued to progress, and maintained their supremacy in the markets of Europe. Nevertheless, they were always in a difficult position, since Italy could not supply them with sufficient raw material, nor could they obtain the number of hands required to carry on all the work connected with their business. To establish branches of the trade in neighbouring states and subject cities was an idea that found no place in the economic and political theories of the Middle Ages. In those days trade formed the chief strength and social power of the communes: hence every commune wished to have the monopoly of its advantages, and the statutes bristled with decrees inspired by this blindly jealous exclusiveness. For this reason, while pursuing the system of keeping the finer and more profitable processes of the manufacture in their own hands, the Florentines had opened factories for the first and coarser stages of the work in every place where the best wool could be found, that is in Holland, Brabant, England, and France. And even in these factories they took care that the more difficult and profitable share of the process should be done only by Florentine hands. Their chronicles prove that they then spoke of foreigners in the same terms now used by the latter with regard to ourselves: jeering at the indolence and stupidity of the northerners, who even on their own soil allowed strangers to snatch the bread from their mouths. But this state of things could not last long. From very early times the Flemings had always been a strong, hard-working race, and were very soon equalled by the French and English. So gradually the eyes of the northerners were opened, and the Florentines saw new factories rising abroad, side by side with and soon rivalling their own, and were obliged to admit that, to their own despite, they had taught foreigners the very trade of which they had meant to preserve the monopoly. Nor was this the end of the matter. Being now on the alert, the northerners tried to check the exportation of their wools and of their uncut, or rather undressed, cloths; and from the end of the fifteenth century Henry VII. of England began to take measures to that effect. Thenceforth the Guilds of Wool and Calimala were doomed to decline in Florence. Fortunately, however, before this came about, the silk trade had assumed the same importance in Florentine commerce that was gradually slipping away from the other two crafts.