SHIELD, a piece of defensive armor, borne on the left arm, to ward off the strokes of the sword and of missiles. It has been constantly used from ancient times through the middle ages, till the invention of fire-arms rendered it useless. The large shield morn by the Greeks and Romans (Gr. aspis, Lat. clipeus) was circular, and often orna mented with devices. Another form of shield (Lat. mutant) was used by the Roman heavy-armed infantry, square, but bent to encircle the bcdy. The early shield or knightly escutcheon of the middle ages was circular in outline, and convex, with a boss ' in the center; the body generally of wood, and the rim of metal. In the 11th c., a form came into use which has been compared to a boy's kite, and is said, with some proba bility, to have been brought by the Normans from Sicily. It was on the shields of this shape that armorial designs were first represented. These shields were iu reality curved like the Roman seutum; but after heraldry began to be systematized, we generally find them represented on seals, monuments, etc., as flattened, in order to let the whole armorial design be seen. In the 13th c.s this long and tapering form began to give place to a pear-shape, and a triangular or heater-shape. During the 14th c., these new forms became more generally prevalent, and the heater-shape, which was perhaps most frequently represented on armorial seals, began to approach more to an inverted equilat eral arch. The same variety of forms, with some modifications, continued during thp 15th c., a tendency appearing in all representations of the heater-shaped shield to gives it more breadth below. A notch was often taken out in the dexter chief for the reecn tion of the lance, in which case the shield,was said to be 6/bow/ie. Subsequent to the mid dle of the 14th c., when the shield came to be depicted as surmounted by the helmet and
crest, the shield is often represented &facia, that is, pendent from the corner, an arrange ment said to have originated in the pradtice of competitors hanging up their shields prior to a tournament, wLere, according to De la Colombibre, if they were to fight on horseback, they suspended it by the sinister chief, and if on foot, by the dexter chief. A square shield denoted a knight-banneret. Shields of arms were often represented as suspended from the guige, or shield-belt, which was worn by the knights to sustain the shield, and secure it to their persons.
After the introduction of fire-arms made shields no longer a part of the warrior's actual equipment, the form of the shields on which armorial bearings were depicted, on seals, monuments, brasses, etc., varied greatly in form, and generally speaking, became gradually more tasteless, fanciful, and Unmeaning. A tendency has, however, been shown in recent heraldry to recur to the artistic forms prevalent in the 14th and 15th ccuturie In early times, shields of the form which generally prevailed at the period were exhibited on the seals and monuments of ladies; but about the 15th c., the practice began, which afterward became usual, of unmarried ladies and widows (the sovereign excepted) bearing their arms-on a lozenge instead of a shield.
The heraldic insignia of towns, corporations. etc., as well as individuals, are placed on shields. The hearing of merchants' marks (q.v.) in a shield was prohibited by the heralds of the 16th c. under severe penalties, and yet not a few instances are to be found on monumental brasses of these devices being placed on shields.