In heraldry and heraldic vexillology, a blazon is a formal description of, most often, a coat of arms or flag, which enables a person to construct or reconstruct the appropriate image. A coat of arms or flag is therefore not primarily defined by a picture, but rather by the wording of its blazon (though often flags are in modern usage additionally and more precisely defined using geometrical specifications). Blazon also refers to the specialized language in which a blazon is written, and, as a verb, to the act of writing such a description.
Other objects, such as badges, banners, and seals may be described in blazon.
A blazon follows a rather rigid formula.
- Every blazon of a coat of arms begins by describing the field (background). In a majority of cases this is a single tincture, e.g. Azure (blue).
- Next the principal charges are named, with their tincture(s); e.g. a bend Or.
- The principal charge is followed by any charges placed around or on it.
A composite shield is blazoned one panel at a time, proceeding by rows from chief (top) to base, and within each row from dexter (the right side of the bearer standing behind the shield) to sinister, i.e. from the viewer's left to the right. A tincture is sometimes replaced by "of the first", "of the second" etc. to avoid repetition of tincture names; they refer to the order in which the tinctures were first mentioned.
A given coat-of-arms may be drawn in many different ways, all considered equivalent, just as the letter "A" may be printed in many different fonts while still being the same letter. For example, the shape of the shield is almost always immaterial.
Because heraldry developed at a time when English clerks wrote in French, many terms in English heraldry are of French origin, as is the practice of placing most adjectives after nouns rather than before.
Full descriptions of shields range in complexity, from a single word to a convoluted series describing compound shields:
- Arms of Brittany, France: "Ermine"
- "Azure, a bend Or", over which the families of Scrope and Grosvenor fought a famous legal battle, see Scrope v. Grosvenor and image above.
- Arms of Östergötland, Sweden: "Gules a Griffin with Dragon Wings, Tail and Tongue rampant Or armed, beaked, langued and membered Azure between four Roses Argent".
- Arms of Hungary dating from 1867, when part of Austria-Hungary, "Quarterly, I three lions' heads affrontés crowned Or (for Dalmatia); II chequy Gules and Argent (for Croatia); III Azure, a river in fess Gules bordered Argent, thereupon a marten proper, beneath a six-pointed star Or (for Slavonia); IV per fess Azure and Or, overall a bar Gules, in the chief a demi-eagle Sable displayed addextré of the sun in splendour, and senestré of a crescent Argent, in the base seven towers three and four, of the third (for Transylvania); enté en point Gules, a double-headed eagle Proper on a peninsula Vert, holding a vase pouring water into the sea Argent, beneath a crown Proper with bands Azure (for Fiume); overall an escutcheon barry of eight Gules and Argent impaling Gules, on a mount Vert a crown Or, issuant therefrom a double cross Argent (for Hungary)".
- Brault, Gerard J. (1997). Early Blazon: Heraldic Terminology in the Twelfth and Thirteenth Centuries, (2nd ed.). Woodbridge, UK: The Boydell Press. ISBN 0-85115-711-4.
- Elvin, Charles Norton. (1969). A Dictionary of Heraldry. London: Heraldry Today. ISBN 0-900455-00-4.
- Parker, James. A Glossary of Terms Used in Heraldry, (2nd ed.). Rutland, VT: Charles E. Tuttle Co. ISBN 0-8048-0715-9.