From about the 12th century, knights wore, flowing surcoats over their armor.  They  usually extended to about mid-calf.  For ease of movement surcoats were normally slit at the front and back. Some surcoats also had slits at the sides.  They appeared in both sleeved and sleeveless.  Surcoats were often emblazoned with the arms of the wearer.

Historians believe that surcoats were worn to protect mail from direct sun, which heated the mail, making the soldier even more uncomfortable than he was before

Men's Surcoat (This one was made for our good friends from Portersville EMS with the EMS "Star of Life" embroidered front and back)

Men's Surcoats (These were made for the Order of Selohaar, with their Guard Corps badge embroidered on the front)