Britannica Sources used in this answer

How did heraldic banners display the arms of their owners?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

flag shapes — flag Various shapes of flags: (from left) rectangle (Algeria), square (Switzerland), pennant (Nepal), swallowtail (Ohio, U.S.).

In medieval heraldry, banners served as a primary means of identification on the battlefield, displaying an owner's arms as if they were a square shield. These banners were distinct from the tapering pennons carried by simple knights; a knight who was privileged to display a square banner in the field was known as a knight banneret.12

The display of arms on these flags was essential for distinguishing between friend and foe, especially as full-body armor made individual identification difficult. While the banner bore the owner's arms directly, other heraldic flags, such as the standard, displayed the principal colors of the arms along with the owner's badge or badges, often featuring the owner's national cross or arms in the hoist.341

It is important to note that while these flags were central to early heraldic identification, they are generally not mentioned in formal written descriptions (blazons) of arms, unless they appear in a modern grant. Today, the use of such banners continues as a way for those who possess arms to display their heraldic identity.51