Why did simple and highly visible designs matter in early heraldry?

In early heraldry, simple and highly visible designs were essential because they served a critical, life-saving function on the battlefield. During the 12th century, as body armor became all-enveloping, it became difficult to distinguish individual knights in the heat of combat.12

Because most of the population was illiterate, these bold, striking symbols provided a reliable visual shorthand to identify combatants, allowing soldiers to quickly distinguish between friend and foe. This need for rapid recognition was paramount; in the chaos of medieval warfare, a mistake regarding the similarity of two opposing devices could—and sometimes did—result in lost battles and death.1

Furthermore, these designs were vital during the Crusades, where they helped differentiate men from various lands who spoke different languages and served different liege lords. While later centuries saw the evolution of more intricate and pedantic designs, the original purpose of heraldry was rooted in the practical, utilitarian necessity of immediate identification.21