Coats of arms identified individuals, not families. A knight might display his coat of arms on his shield so he could be identified in battle. He might also display it on a banner or flag in front of his tent, again, so he could be identified.
Arms were registered so that no two people would have the same arms.
The symbol on the knight's shield was his family's coat of arms.
A knight's personal flag is called a heraldic banner or a personal coat of arms. It typically features a unique design that represents the knight's family lineage, achievements, and values.
A medieval family crest is a symbol or "coat of arms" that represents a certain family with knights in their ancestry. A knight may have carried this crest on his shield.
The logo or picture on a knight's shield is called a coat of arms. It typically includes symbols and colors that represent the knight's identity, family, or allegiance.
In countries like the united kingdom, where there is a continuing history of official use and regulation of Coats of Arms, you can get Arms if you are determined to be eligible to display a coat of arms. A coat of arms is issued to one person, not a family and this is decided by the office of heralds or the King of Arms. If you do not have authorization from the heralds you are not able to display any coat of arms. The rules for determining who is eligible to display a coat of arms are very similar to the rules for becoming King or Queen. However, even the proper heir cannot display the coat of arms until he or she has received authorization by the heralds. At any one time, only one person my rightfully display a coat of arms. To find out more about this the British government operates a web site. However in countries like the United States, where heraldry is not regulated, there is no limitation on the creation or display of Coats of Arms. There is also little value in recently created Coats of Arms since there is no limitation on them
The knight had his coat of arms on his shield.
They didn't. There is no such thing as a family coat of arms - this is a modern scam developed by fake genealogy tradespeople who prey on ignorant and gullible customers. Just because your surname is Fitzwalter or Grosvenor (for example) you would have absolutely no claim to the Fitzwalter or Grosvenor coat of arms unless you are heir to the title and estate (and you would certainly be aware of that).Heraldry has always been issued on an individual basis, mainly to knights when they win their spurs or are knighted for outstanding deeds. A knight would pass on that heraldry to his eldest son, but nobody else in his family (and nobodywith the same family name) is entitled to use that heraldry.So a man might have a specific coat of arms and his brother might have an entirely different coat of arms. His wife, who might have entitlement to her own coat of arms, might combine her own and her husband's heraldry in a lozenge (not a shield).Modern English knighthoods are generally awarded for outstanding service in business, sport or politics; these are generally not hereditary, so the new knight would have a coat of arms along with his title, but he can not then pass it on to his eldest son.
because it would represent which king or kingdom and what team they were on in the battlefield so that each knight would know who to fight.
the purpose of the coat of arms on a knight were so he could be identified on the battlefield.
to distinguish who he fights for
A family coat of arms can be found from past members of the family or created new. It is unusual to wear one except as a piece of jewelry. Usually coats of arms are hung on the wall. Anyone who is proud of their heritage could wear one.