A flag in heraldry is both a symbol and a system of display: it signals identity at a distance, marks presence, and declares allegiance or authority. In medieval and early modern Europe, the practical need to be recognized in ceremony and on campaign helped turn “a flag” into a family of distinct heraldic flags, each tied to the owner’s armorial identity. Modern heraldry still treats these as meaningful extensions of the coat of arms, not mere decoration, which is why you will often see them described alongside shields, crests, and badges in guides to heraldic flag types (Heraldic flag).

In strict heraldic terms, the most direct translation of a coat of arms into cloth is the banner of arms: the full shield design, copied exactly onto a square or rectangular flag (Banner of arms). Other forms emphasize different messages. A standard typically highlights livery colours, badges, and sometimes a motto, projecting following and command rather than the entire shield, while a pennon or guidon can function as a more personal or tactical ensign (Heraldic flag). As a symbol, the flag therefore leans toward themes of leadership, proclaimed loyalty, service, and collective identity, especially when paired with supporters, ranks, or orders.

For concrete examples, Wikipedia notes that the banners of members of chivalric orders are famously displayed in their chapels, such as Garter banners in St George’s Chapel, Windsor, and Thistle banners in St Giles’ Cathedral, Edinburgh (Heraldic flag). For image-rich browsing of how flags appear as charges, accessories, or held by figures in achievements, see Category:Flags in heraldry (Wikimedia Commons).