The poleyn was a component of Medieval and Renaissance armor that protected the knee. During the transition from mail armor to plate armor, this was among the earliest plate components to develop. They first appeared in the mid-thirteenth century and remained in use until the early seventeenth century when firearms made them obsolete.

The poleyn was a component of Medieval and Renaissance armor that protected the knee. During the transition from mail armor to plate armor, this was among the earliest plate components to develop. They first appeared in the mid-thirteenth century and remained in use until the early seventeenth century when firearms made them obsolete.