A Burgmann was a member of the low aristocracy

Aristocracy

Aristocracy , is a form of government in which a few elite citizens rule. The term derives from the Greek aristokratia, meaning "rule of the best". In origin in Ancient Greece, it was conceived of as rule by the best qualified citizens, and contrasted with monarchy...

 in the Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 who guarded and defended castle

Castle

A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...

s. They were hired by a lord of the castle to take on the burghut, the guarding and defense of a castle.

Although they were paid for their services, they had to provide their own armor. In the late Middle Ages, the system of burgmann disappeared and the castles were protected by landsknecht

Landsknecht

Landsknechte were European, predominantly German mercenary pikemen and supporting foot soldiers from the late 15th to the late 16th century, and achieved the reputation for being the universal mercenary of Early modern Europe.-Etymology:The term is from German, Land "land, country" + Knecht...

.