These markets are a great chance to remember that although Hamburg is a
rather modern city, it happens to be 1200 years old. They are very interesting events, where you get to try local beer and dishes (prepared the medieval way), see a little of the traditions from the Germans of the Middle Ages,enjoy medieval music shows and buy 'medieval' handicrafts and costumes. It's also a great chance to get to know the locals.
People may have the first impression that Hamburger people are cold and unfriendly but in events like this one, you'll get to see the warmth and friendliness of the locals. Unfortunately these markets aren't permanent, so you have to ask the locals or look in the local papers and magazines or pay attention to the advertisement on the streets.