As explained in how heraldry began, heraldry was first created in order to help identify who was who in which armor. After all, you wouldn't want to accidentally kill a knight that was really your neighbor
unless he was a jerk, correct? Emblems of geometric shapes as
well as the more recognizable birds, beasts and symbols were then used to
decorate shields. The shield not only offered protection, but
identification as well. The shield is a big, flat surface -- perfect for
painting a design on. It is also harder to damage and is in sight more
than a tunic or cloak, nor can it be as easily stolen as a pennant (Slater
12-21).
Shields, then, became the medieval version of a driver's license. Even though it was next to impossible to tell the eye color and age of the knight in the suit of armor with the shield of a gold griffon on a blue field, it was possible to tell the morals and the way his family acts through identifying the colors and symbols on his shield.
Heraldry fully developed not on the battlefield, however, but within the tournaments. The tournaments were akin to present-day ESPN, where the nobility (or athletes, in present day's case) competed, each boasting of their skills. The most famous of tournament games was jousting, where two knights on horseback would charge at each other with lances, and the victor was the one who unhorsed his opponent or broke the most lances. The peasantry who watched these "games" were unable to read the scoreboards like sports fans do in present-day games. Hence, heraldry was developed to identify knights based on their shield
design (22-24). These practice is applied again in some cases of family trees as
well (116-118).
