"The SCA is an international organization dedicated to researching and re-creating the arts and skills of pre-17th-century Europe. Our "Known World" consists of 19 kingdoms, with over 30,000 members residing in countries around the world. Members, dressed in clothing of the Middle Ages and Renaissance, attend events which may feature tournaments, arts exhibits, classes, workshops, dancing, feasts, and more. Our "royalty" hold courts at which they recognize and honor members for their contributions to the group."
There is more information to be had at their website, including information about local groups that might be close to you.
For me, I enjoy researching, studying and trying to recreate the arts and sciences of these time periods (i.e., weaving, sewing, cooking, etc.). The best part, however, is when I get together with groups of other people who are interested in the same things. We can swap information and learn from each other, as well as, just socialize.
NOTE: These comments and opinions are expressly those of the author and in no way to be construed as official or unofficial opinions of the Society for Creative Anachronism, Inc.