A rerebrace (sometimes known as an upper cannon^[1]) is a piece of armour designed to protect the upper arms (above the elbow). Splint rerebraces were a feature of Byzantine armour in the Early Medieval period. The rerebrace seems to have re-emerged in England, in the early 14th century.^[2] As part of the full plate armour of the Late Middle Ages and Renaissance the rerebrace was a tubular piece of armour between the shoulder defences (spaulder or pauldron) and the elbow protection (couter).

• Cleveland Museum of Art glossary of arms and armor

v t e Components of medieval European armour
Head	Armet Barbute Bascinet Burgonet Cervelliere Enclosed helmet Close helmet Great helm Frog mouth Hounskull Lobster tail pot Mail coif Morion Nasal helmet Sallet Spangenhelm Kettle hat
Face	Visor Falling buffe
Neck	Aventail Bevor Gorget Pizaine
Torso	Breastplate Brigandine Cuirass Culet Pauncer Plackart Fauld Hauberk Codpiece Lance rest Coat of plates Jack of plate
Arms	Ailette Besagew Couter Gauntlet Pauldron Rerebrace Spaulder Vambrace
Legs	Bases Chausses Cuisses Greave Poleyn Sabaton Schynbald Tasset
Pieces	Gousset Lame Rondel Arming points