(via https://en.wikipedia.org/wiki/Guild)

Roman craftsman's organizations continued to develop in Italy of the Middle Ages under the name ars. In Germany they are first mentioned in the 10th century. The German name is Zunft (plural Zünfte) for guilds of craftsman and Gilde (plural Gilden) for guilds of merchants. Métiers in France and craft gilds in England emerged in the 12th century.“ Guild#Early_guildlike_associations

The early egalitarian communities called “guilds” (for the gold deposited in their common funds) were denounced by Catholic clergy for their “conjurations”—the binding oaths sworn among artisans to support one another in adversity and back one another in feuds or in business ventures. The occasion for the drunken banquets at which these oaths were made was December 25, the pagan feast of Jul: Bishop Hincmar, in 858, sought vainly to Christianize them. Guild#European_history

An important result of the guild framework was the emergence of universities at Bologna, Paris, and Oxford around the year 1200; they originated as guilds of students as at Bologna, or of masters as at Paris. Guild