Western European trade associations, grew strongly in the 12th and 13th centuries to protect and promote trade groups. Data from the Brewersâ€(tm) Company in London show that their were at least 14 different guilds concerned with leather listed in London in 1422).
During the Middle Ages, craftsmen, artisans and merchants formed organizations that regulated most aspects of its members' businesses. Guilds dictated the requirements for membership and controlled the training of apprentices as well as the quality and price of services or merchandise offered by its members. Non-members were forbidden to practice their crafts and preferential treatment was often afforded to guild members. By the end of the Middle Ages, guilds became extremely powerful, influencing the economic and political life of towns throughout Europe as well as international trade. They often had their own patron saint and staged elaborate processions that both honoured their patrons and provided a form of medieval advertising. Guild halls were often the political centre of towns and, at times, the statutes of guilds were adopted by the town as civic statutes.