Brigand

BRIGAND, brig' end n one who lives by plunder usually as a member of a band. (Webster)

[A brigandine] was a piece of medieval armor consisting of thin jointed scales of plate metal, usually sewed on linen or leather to form a tunic. It came into common use because it was lighter than the corselet made of two or three large fitted plates, more effective than the chain mail hauberk, and cheaper than either.

The name [brigandine] came from the brigands, a lightly armed irregular soldiery of the 14th and 15th centuries, mainly in France, who lived as highwaymen or ventured from castles to ransack the countryside. (Encyclopedia Americana, Brigandine)