In heraldry and heraldic vexillology, a blazon is a formal description of a coat of arms, flag or similar emblem, from which the reader can reconstruct the appropriate image. The verb to blazon means to create such a description. The visual depiction of a coat of arms or flag has traditionally had considerable latitude in design, but a verbal blazon specifies the essentially distinctive elements. A coat of arms or flag is therefore primarily defined not by a picture but rather by the wording of its blazon (though in modern usage flags are often additionally and more precisely defined using geometrical specifications). Blazon is also the specialized language in which a blazon is written, and, as a verb, the act of writing such a description. Blazonry is the art, craft or practice of creating a blazon. The language employed in blazonry has its own vocabulary, grammar and syntax, which becomes essential for comprehension when blazoning a complex coat of arms.
The noun and verb blazon (referring to a verbal description) are not to be confused with the noun emblazonment, or the verb to emblazon, both of which relate to the graphic representation of a coat of arms or heraldic device.
The word blazon is derived from French blason, "shield". It is found in English by the end of the 14th century.
Blazon is generally designed to eliminate ambiguity of interpretation, to be as concise as possible, and to avoid repetition and extraneous punctuation. English antiquarian Charles Boutell stated in 1864:
Heraldic language is most concise, and it is always minutely exact, definite, and explicit; all unnecessary words are omitted, and all repetitions are carefully avoided; and, at the same time, every detail is specified with absolute precision. The nomenclature is equally significant, and its aim is to combine definitive exactness with a brevity that is indeed laconic.
However, John Brooke-Little, Norroy and Ulster King of Arms, wrote in 1985: "Although there are certain conventions as to how arms shall be blazoned ... many of the supposedly hard and fast rules laid down in heraldic manuals [including those by heralds] are often ignored."
A given coat of arms may be drawn in many different ways, all considered equivalent and faithful to the blazon, just as the letter "A" may be printed in many different fonts while still being the same letter. For example, the shape of the escutcheon is almost always immaterial, with very limited exceptions (e.g., the coat of arms of Nunavut, for which a round shield is specified).
The main conventions of blazon are as follows:
Party per pale argent and vert, a tree eradicated counterchanged. Arms of Behnsdorf.
Argent, an eagle displayed gules armed and wings charged with trefoils Or. Arms of Brandenburg.
Quarterly 1st and 4th Sable a lion rampant on a canton Argent a cross Gules; 2nd and 3rd quarterly Argent and Gules in the 2nd and 3rd quarters a fret Or overall on a bend Sable three escallops of the first and as an augmentation in chief an inescutcheon, Argent a cross Gules and thereon an inescutcheon Azure, three fleurs-de-lis Or. Arms of Churchill.
Because heraldry developed at a time when English clerks wrote in Anglo-Norman French, many terms in English heraldry are of French origin. Some of the details of the syntax of blazon also follow French practice: thus, adjectives are normally placed after nouns rather than before.
A number of heraldic adjectives may be given in either a French or an anglicised form: for example, a cross pattée or a cross patty; a cross fitchée or a cross fitchy. In modern English blazons, the anglicised form tends to be preferred.
Where the French form is used, a problem may arise as to the appropriate adjectival ending, determined in normal French usage by gender and number.
"To describe two hands as appaumées, because the word main is feminine in French, savours somewhat of pedantry. A person may be a good armorist, and a tolerable French scholar, and still be uncertain whether an escallop-shell covered with bezants should be blazoned as bezanté or bezantée". (Cussans)
The usual convention in English heraldry is to adhere to the feminine singular form, for example: a chief undée and a saltire undée, even though the French nouns chef and sautoir are in fact masculine. Efforts have however been made, for example by J. E. Cussans, who suggested that all French adjectives should be expressed in the masculine singular, without regard to the gender and number of the nouns they qualify, thus a chief undé and a saltire undé.
Full descriptions of shields range in complexity, from a single word to a convoluted series describing compound shields:
Quarterly I. Azure three Lions' Heads affronté Crowned Or (for Dalmatia); II. chequy Argent and Gules (for Croatia); III. Azure a River in Fess Gules bordered Argent thereon a Marten proper beneath a six-pointed star Or (for Slavonia); IV. per Fess Azure and Or over all 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 Gules (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); over all 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).