A coat of arms was the heraldic symbol displayed on a knight’s shield and often on his surcoat. Heraldic designs helped identify an armored person when a helmet and face covering obscured individual features.
The shield was the central surface for heraldic display, while the surcoat was a garment worn over armor. Designs could include colors, geometric divisions, animals, plants, or mythical creatures. Over time, coats of arms became hereditary in many European societies, although rules and customs differed among regions.
Heraldry developed during the High Middle Ages alongside tournaments, warfare, and the growth of noble families. A complete achievement of arms could include a shield, helmet, crest, supporters, motto, and other elements. The shield itself is not identical to the entire achievement.
A coat of arms was also not simply a personal logo chosen freely in every historical context. Heraldic authorities and local traditions governed recognition and inheritance. Modern institutions, towns, and universities may also possess coats of arms.