Guilds

Were groups of tradesmen who got together to make things and make them well. They had their trade secrets and they were monopolies. But they helped civilization along over hundreds of years. It turns out that they were not just English or even European. There were equivalents on other continents.

Guilds
QUOTE
A guild is an association of craftsmen in a particular trade. The earliest guilds were formed as confraternities of workers. They are organized in a manner something between a trade union, a cartel and a secret society. They often depended on grants of letters patent by an authority or monarch to enforce the flow of trade to their self-employed members, and to retain ownership of tools and the supply of materials..... The modern patent system was setup to break the power of the guilds.

Early guilds AD 300 - 600
In pre-industrial cities, craftsmen tended to form associations based on their trades, confraternities of textile workers, masons, carpenters, carvers, glassworkers, each of whom controlled secrets of traditionally imparted technology, the "arts" or "mysteries" of their crafts. Usually the founders were free independent master craftsmen.

European history
In the Early Middle Ages most of the Roman craft organizations, originally formed as religious confraternities, had disappeared, with the apparent exceptions of stonecutters and perhaps glassmakers. Gregory of Tours tells a miraculous tale of a builder whose art and techniques suddenly left him, but were restored by an apparition of the Virgin Mary in a dream. Michel Rouche remarks that the story speaks for the importance of practically transmitted journeymanship.

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 26, the pagan feast of Jul [ Yule ]:.....

By about 1100, European guilds and livery companies began their medieval evolution into an approximate equivalent to modern-day business organizations such as institutes or consortia.............

European guilds imposed long standardized periods of apprenticeship, and made it difficult for those lacking the capital to set up for themselves or without the approval of their peers to gain access to materials or knowledge, or to sell into certain markets, an area that equally dominated the guilds' concerns. These are defining characteristics of mercantilism in economics, which dominated most European thinking about political economy until the rise of classical economics.......
UNQUOTE
That is fairly complete. Guilds had their weaknesses which is why they fell. They have virtues too.