A gambeson is a padded surcoat, usually worn underneath flexible metal or leather armour, such as a chainmail shirt. The gambeson is often produced with a sewing technique called quilting. The gambeson was vital in preventing crushing damage, since even if the edge or point of the weapon was stopped by the exterior armour, the remaining impact could still splinter bone and rupture internal organs. The gambeson distributed the impact over a larger area, and absorbed some energy by deforming.
For soldiers who could nor afford a harder, more expensive exterior armour, the gambeon was often the only armour available. As a gambeson is very labour intensive in the making, most common soldiers would have to produce their own.
The gambeson can at least be traced to the late 10th century, but it is likely to have been in use in various forms for longer than that. Use of the gambeson declined during the renaissance, and by the 17th century, it was no longer in military use.
Several different patterns were used, and the form of the gambeson varied throughout the middle ages and the renaissance due to the ever increasing percentage of the body protected by rigid steel armour. Usually constructed of linen or wool, the stuffing varied, and could be for example scrap cloth or horse hair.