An invincible knight's sword remains firmly clutched in your mail-clad fist and your banner floats in the wind as your squire buckles on your rugged 13th-century crusader knight's helm for battle. The perforated faceplate facilitates ventilation as you fight your enemy and protects you from arrows raining down on you and your fellow knights, waiting for the order to charge!
In the 12th century, knights quickly realized that with the new technique of the placed spear becoming more widespread, it was essential to have additional protection for the face, since most of the spear blows that passed over the shield they would instantly kill a knight wearing the ancient style of nose helmet. Early on, they added a front plate to offer additional protection against all attacks coming from the front, proving remarkably efficient against enemy archers and mounted opponents. (Later, more plates were added to cover the back of the neck and completely enclose the head: the pot/great helm was born. But that's another story.)