The shield as part of a coat of arms was adopted from the equipment of a knight. As the central part of a coat of arms, it displays the heraldic figure and gives the coat of arms its particular outer form. As a rule, the shield will contain a single tincture or a single motif; it may however also be divided into combinations of parted and varied fields containing several heraldic figures or symbols.
The horseman’s shield of the High Middle Ages was developed on the pattern of the so-called ‘Norman’ shield, a kite-shaped shield of the 11th century. ‘Norman’ shields were relatively big shields, long and narrow; they had rounded tops. Already around 1200 this Romanesque shield, with its form comparable to an almond, was replaced by the Gothic and triangular shield known as heater shield. This new shield was significantly smaller, easier to handle, and permitted greater freedom of movement.
About 1360 the Spanish semi-circular shield came into more widespread use. Its pleasant shape and its large surface allowed for a generous layout of fields, especially so for coats of arms with several figures or symbols, or for coats of arms with parted and varied fields.