During the late middle ages, in various city-states of what is now modern Italy, various guilds involving carefully defined membership and procedures were operating as legal authoritative bodies. One of these was the silk guild, which defined the manner of making silk and related apparel products by its membership. The rules by the guilds amounted to giving their members a monopoly for a given period of time. Usually, members of a guild worked as apprentices and, after a given period of time, they became journeyers or other elevated category based on their skill and expertise, including master craftsmen. The earliest guilds appear to have existed in India as early as 3800BCE .

More particularly, the Venetian Statute of 1474 specified that new and inventions devices (especially those involved in making cloth and cloth products) must be disclosed to the Republic of Venice to obtain protection against infringers and copiers. The period of protection was 10 years. Nevertheless, various "letters patent" (or "open letters" as opposed to "sealed letters") were issued by monarchies and other authoritative bodies, e.g., King Henry VI, to individuals for various products before 1474. [wikipedia (20071204): "history of patent law"]

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