Society for Creative Anachronism 
The SCA is a medieval re-enactment society. Think, combination costume party and history group. It is a non-profit incorporated society, with over 50,000 paid members. I have no idea on how many unpaid members, but it would be a lot more?! While the SCA was started in the USA over 30 years ago, it has grown to encompass the world (to varying degrees), with branches in bizarre locations like Antarctica, and on the USS Enterprise. The globe is divided into sixteen organisational "Kingdoms", and then sub-divided into the smaller local groups of members.
People normally pick a place, and time period, to research. The SCA is different from most re-enactment groups, in that it does not cover just one era, but covers 600 AD - 1650 AD world-wide. So you may find an Elizabethan rubbing shoulders with a Mongol. This is both good and bad, but makes at least makes events more colourful. Often people will try to get as realistic as possible for their chosen specialisation. This will include looking, acting, smelling (!), and generally emulating someone from their era when attending events. I have done a reasonable amount of research into Mongols of the "golden time", The first half of the 13th century. I found myself branching out to learn about the other civilisations the Mongols interacted with, and am still learning whenever I have time.
I am known as Lord Ozbeg Mangudai when attending such events, and have left my local group of Ildhafn of the Kingdom of Caid (California, NZ, Hawaii), for the delights of the shire of Thamesreach, in the Kingdom of Drachenwald (selected Western Europe). (EDIT: Well it's been so long now, Ildhafn has split off Caid?!)
Recreating 14th century tournament combat is one thing I enjoy doing, along with other diverse activities such as brewing (and drinking), period dancing, juggling, medieval morals & philosophy, cultural strategy & tactics (long live Subadai!). Just about anything really.
Please Email me if you want more information on either the SCA in general, or events in southern England.
For pictures of me in SCA costume, and details about who I am mundanely, click HERE.
