From the dawn of history, long before we could read or write we used symbols and emblems to convey our ideas. In the days of the Empire, the Romans carried the eagle atop their standards as a symbol of strength. The old Celtic clans used a system of colours to indicate social and political precedence; the ullamh or professor ranked highest with seven colours. The is also a recorded coat of arms attributed to Cass, king of North Munster in the third century, although, heraldry as we know it only came into existence during the twelfth century. An instantly recognizable device to distinguish friend from foe was required at this time, due to the introduction of coat mail, which covered combatants from head to foot in grey steel. The primary and other bright colours were the obvious choice and these were so painted on the shields as to be easily recognized at a distance without margin or error.
Under most heraldic rules, only first sons of first sons of the recipient of a Coat of Arms are permitted to bear their ancestor’s Arms. Younger sons may use a version of their father’s Arms, but the rules of heraldry say that they must be changed (‘differenced’) somewhat. If the bearer of a Coat of Arms (called an (‘Armiger’) dies without male heirs, his daughter may combine her father’s Arms with her husband’s Arms. This process is called ‘impaling’. Although these principles seem formal today, they do give us an idea of the rich, protective tradition which surrounded heraldry through the ages.