How did knights use heraldry?

Answer 1

It is not clear whether you are asking about how knights chose their heraldry, or how it was used on the battlefield.

Throughout the medieval period, from about the 1140s, heraldry was widespread in Europe but almost completely unregulated. The few rules that were applied differed from one country to another and in the first stages of its development there were no rules at all.

When a man was created a knight he was entitled to have a coat of arms which could be displayed on his shield; middle and higher grades of knights might also have a banner displaying their heraldry - this banner would be carried by a member of the knight's retinue and symbolised the knight's presence. Some knights had heraldry that reflected their family name (such as seven winnowing fans for a knight of the Septvans family, or a wild boar for Hogg). Others simply chose a random design for themselves, or had one allocated to them by the king himself - Henry II allocated a coat of arms to his favourite huntsman which included three lions (from the royal arms).

As well as the heraldry on the shield (the arms), a knight might also choose to have a heraldic badge such as an eagle, stag or rose, which would be worn on the clothing of all his servants and retainers; he might also have a crest which could feature as a wooden or paper mache sculpture on top of his helmet. The badge and crest did not have to have any connection at all with the coat of arms.

The job of a herald was to learn by heart all the coats of arms of the knights in his own army and those of prominent knights in the enemy's army - a considerable task calling for an immensely good memory.

Answer 2

There is disagreement on why/how heraldry came about, and what it was used for occasionally. One belief goes that with the development of armor a knight could not be recognized during combat, so the coat of arms signaled who he was. Another belief is that the original crests were ornaments similar to the way modern soldiers create logos they wear and put on patches and other articles (see example in link below), but with the advent of armor they came to serve the above described purpose. Subsequently, because knights were paid with land and status heraldry was used to identify the family and thus its status and were passed down to heirs.

Answer 3

Knights and others used coats of arms to allow themselves to be recognized in battle even though they were encased in armor. They also used them as a means of identification when not in battle because few if any of them could read.

Answer 4

to show that they were them.