How Did Family Coats Of Arms Get Created Originally?

          It was pretty ad hoc to begin with.

          In medieval times a knight (warrior) usually wore a kind of outer coat --  called a surcoat.  This was typically padded linen over metal, and served to give extra protection from sudden attack, and to insulate the knight from excess heat (the sun warming chain mail) or cold.

          It was on this metal outer coat that knights would usually paint their colours and symbols; hence the birth of the expression "coat of arms".  This was in an age when few people could read, so symbols meant a lot.  Moreover, in the heat of battle there wasn't time to read somebody's name tag -- having a quickly recognisable set of colours and symbols made much more sense, in terms of identifying friend or foe.

           Originally the heraldic symbols might represent either the knight's family or the man as an individual.  But he would pass the symbols down to his sons, if he was lucky enough to become that powerful.

           Over time, it became conventional to display these personal and family symbols on one's other personal possessions, including defensive shields, decorations, and standards (personal flags) of powerful families.

            The most enduring coats of arms were those handed down in the most powerful families, those who became Kings and Queens and aristocracy in each country.

          Nowadays, if you want to know what famly coats of arms you can realistically lay claim to, you must research your own family tree very carefully, to figure out whether your specific ancestors were anybody important.