In heraldry

Heraldry

Heraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...

, gules (icon) is the tincture

Tincture (heraldry)

In heraldry, tinctures are the colours used to emblazon a coat of arms. These can be divided into several categories including light tinctures called metals, dark tinctures called colours, nonstandard colours called stains, furs, and "proper". A charge tinctured proper is coloured as it would be...

 with the colour red

Red

Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...

, and belongs to the class of dark tinctures called "colours". In engraving

Engraving

Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

, it is sometimes depicted as a region of vertical lines or else marked with gu. as an abbreviation.

In Polish heraldry

Polish heraldry

Polish heraldry is a branch of heraldry focused on studying the development of coats of arms in the lands of historical Poland , as well as specifically-Polish traits of heraldry. The term is also used to refer to Polish heraldic system, as opposed to systems used elsewhere, notably in Western Europe...

, gules is the most common tincture of the field. Through the sixteenth century, nearly half of all noble coats of arms

Coat of arms

A coat of arms is a unique heraldic design on a shield or escutcheon or on a surcoat or tabard used to cover and protect armour and to identify the wearer. Thus the term is often stated as "coat-armour", because it was anciently displayed on the front of a coat of cloth...

 in Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 had a field gules with one or more argent

Argent

In heraldry, argent is the tincture of silver, and belongs to the class of light tinctures, called "metals". It is very frequently depicted as white and usually considered interchangeable with it...

 charges on them.

The gules tincture is said to represent the following:

• of jewels, the ruby
  Ruby
  A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum . The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires...
  
  ;
• of heavenly bodies, Mars
  Mars
  Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
  
  ; the planet Mars is further associated with the metal iron in traditional alchemical occultistic lore
  Classical planets in western alchemy
  Alchemy in the Western World and other locations where it was widely practiced was allied and intertwined with traditional Babylonian-Greek style astrology; in numerous ways they were built to complement each other in the search for hidden knowledge...
  
  .

Etymology

The term "gules" derives from the Old French

Old French

Old French was the Romance dialect continuum spoken in territories that span roughly the northern half of modern France and parts of modern Belgium and Switzerland from the 9th century to the 14th century...

 word goules, literally meaning "throats" (related to the English gullet; modern French gueules), but also used to refer to a fur neckpiece, usually made of red fur.

For many decades, heraldic authors have believed that the term may have arisen from the Persian

Persian language

Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

 word gol "rose" (coming to Europe via Muslim Spain or brought back by returning Crusaders), but according to Brault there is no evidence to support this derivation.