Developed as a low wall that surrounded a Keep - which protected it's base. Sometimes called an Apron Wall or Mantlet. The Chemise system's initial design may have evolved from the earlier Mottle and Bailey system. Often access to a Keep could only be made through a Chemise. Often incorporated into the later Bastion defensive system ( as a way of reinforcing the central defensive structure). The Chateau de Vincennes, in France is still in exsitence and is an excellent example of the Chemise.