Stripped for battle

What is the origin of the phrase "stripped for battle?" Which picture should come to our minds when such a phrase is used?

I've been trying to imagine what sort of warrior strips for battle. Normally one expects warriors to gird for battle. Prize fighters strip down in a way of speaking, but the shorts that they wear are not their underwear. When women come onto the Jerry Springer show to do battle they often kick off their shoes right at the start, but I wouldn't call that stripping for battle. (Sometimes they do strip DURING the battle, however.) What picture comes to mind? A picture of shivering guys wearing helmets and carrying swords. SS