Poleyn

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.
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The period name for what is known in modern SCA verbiage as the "knee cop," the defense of the knee. During the early 14th century, rondels were laced to the mail to improve the defense of the leg and add to the defense offered by a mail chausse. By 1320 these rondels had been replaced by a fully-encompassing "gutter" around the knee itself, laced into place or attached to a leather or gamboised or splinted cuisse at the top and the same construction of greave to the bottom. By 1350 the poleyn was articulated with lames ; a heart-shaped wing was then extended from the poleyn itself to provide more protection for the back of the knee. After this point the poleyn decreased steadily in size, providing for a better platform for the articulation of the joint. This wing expanded and, with minor variations, remained reasonably constant in shape (though larger) throughout the 15th century. 14th century poleyns were generally articulated with no more than three lames, one on top and one or two between the demi-greave and poleyn itself. See also leg harness .