The Order of Brothers of the German House of Saint Mary in Jerusalem (Official names: , ), commonly the Teutonic Order (Today: German Order = Deutscher Orden, also Deutschherrenorden or Deutschritterorden), is a German medieval military order, and became in modern times a purely religious Catholic order. It was formed to aid Christians on their pilgrimages to the Holy Land and to establish hospitals. Its members have commonly been known as the Teutonic Knights, since they also served as a crusading military order in the Middle Ages. The military membership was always small, with volunteers and mercenaries augmenting the force as needed.