The Royal Coat of Arms of the United Kingdom of Great Britain and Northern Ireland is the arms of dominion of Her Majesty Queen Elizabeth II in right of the United Kingdom and consequently is used as the official coat of arms of the United Kingdom itself.

Table of contents
1 Present Coat
2 History of this coat
3 Blazon

Present Coat

The shield is quartered, depicting in the first and fourth quarters the three lions passant guardant of England; in the second, the rampant lion and double tressure fleury-counter-fleury of Scotland; and in the third, a harp for Northern Ireland (previously for Ireland).

The crest is a lion statant guardant wearing the imperial crown, itself on another representation of that crown.

The dexter supporter is a likewise crowned lion, symbolizing England, and a unicorn symbolizing Scotland. (The unicorn is chained because in mediaeval times a free unicorn was considered a very dangerous beast (only a virgin could tame a unicorn).)

The coat features both the motto of British Monarchs Dieu et mon droit (God and my right) and the motto of the Order of the Garter, Honi soit qui mal y pense (Shamed be he who thinks ill of it) on a representation of the Garter behind the shield.

When displayed in Scotland, the Queen's personal coat changes so that the quarters are I and IV, Scotland; II, England; and III, Northern Ireland. The supporters also change sides; the unicorn is imperially crowned, and is sometimes depicted gorged of an Eastern crown (with pointed ends) rather than a coronet of crosses and fleurs de lis, and both supporters hold banners. The unicorn holds a banner of St Andrew, and the lion a banner of St George. The Scottish crest (a lion sitting on a crown, holding a sword and a sceptre) is used instead of the royally crowned lion. Two Tudor Roses are also in evidence.

History of this coat

The Coat of Arms of England, gules three lions passant or, was used by the early Kings of England. In 1328, King Edward III claimed the French throne through his mother Isabella, but the French suggested that the throne could pass through the male line only due to Salic law. Edward III quartered the arms of England with the arms of France, azure a semy of fleurs de lis or; to indicate the importance he placed on France, the French arms were placed in the first and last quarter, and the English ones in the second and fourth. Henry IV changed the French quarterings from a semy of fleurs de lis to only three fleurs de lis.

When James VI of Scotland came to the throne of England in 1603, the arms changed to reflect France, England, Scotland, and Ireland (which had been ruled by the Sovereign of England since 1541). The first and last quarters were divided into four grandquarters each, and bore the arms of France and England. The second quarter of the coat bore the arms of Scotland, or a lion rampant gules within a double tressure flory counterflory gules, while the third quarter bore the arms of Ireland, azure a harp or.

When William, Prince of Orange ruled along with Mary II, an estucheon of pretence, bearing the arms of Nassau, azure billetty and a lion rampant or, was added to represent William III's dynasty. When Anne succeeded to the throne, the estucheon was removed. Furthermore, the quarterings were changed: the first and fourth quarters each contained the arms of England and Scotland impaled, the second quarter the arms of France, and the third the arms of Ireland.

When the Hanoverian George I succeeded to the throne, the fourth quarter changed to the arms of Hanover: tierced per pale and per chevron - I gules two lions passant or; II or a semy of hearts gules a lion rampant azure; III gules a horse courant argent; overall an escutcheon of pretence gules charged with the crown of Charlemagne.

George III renounced the ancient British claim to France in 1801. The arms were changed to: I and IV, England; II, Scotland; III, Ireland. In the centre was placed an estucheon of pretence bearing the aforementioned arms of Hanover. Above the estucheon was a bonnet representing the Electorate of Hanover; the bonnet changed to a crown when Hanover became a Kingdom.

The estucheon for Hanover was removed when Victoria became Queen, but failed to inherit the Kingdom of Hanover, which could only pass to a male. Queen Elizabeth II inherited this coat as her personal arms upon the death of her father, George VI. The Queen is the only lady in England who is entitled to bear her personal arms upon a shield with a crest, rather than on a lozenge.

Some texts erroneously state that during the time that the British monarch also claimed the imperial throne of India, the royal crown was changed to the imperial crown (similar but with the centre depressed). When imperial rule of India ceased, the royal crown returned. This is based upon a misunderstanding regarding the crown emblazoned in British royal heraldry, which is described in blazon as an imperial crown, i.e. a crown with four arches. There are two main styles of crown that have been used over the years, one with indented arches (St Edward's Crown) and one without (the Imperial State Crown), which are based on actual crowns belonging to the Crown Jewels. The actual crown shown has been a choice of the monarch of the time. Curiously, because both Victoria and Elizabeth II chose one crown and the various Kings between them chose the other, there is also a common misconception that they comprise distinct Kings' and Queens' crowns, which they do not. In Scotland there is one style of crown, based on the Honours of Scotland, which has a coronet of fleurs-de-lys and four low-set arches surmounted by a cross and orb.

Blazon

Arms: Quarterly I & IV England (gules, three lions passant guardant in pale Or, armed and langued azure); II Scotland (Or a lion rampant, within a double tressure fleury-counter-fleury gules); III Ireland (azure, a harp Or stringed argent. This is depicted within a Garter with the words Honi soit qui mal y pense. The Scottish version of the arms is Quarterly I & IV Scotland, II England, III Ireland, and depicted within a collar of the Order of the Thistle.

Crest (England): Upon the Royal helmet an imperial crown proper, thereon statant gardant Or, a lion statant imperially crowned also proper.

Crest (Scotland): Upon an imperial crown proper a lion sejant affronté gules, imperially crowned or, holding in his dexter paw a sceptre, and in his sinister a sword, both proper.

Crest (Ireland): On a torse azure and or, a castle triple-towered of the second, from the portal thereof a hart springing argent attired and hooved or. The Irish royal crest is rarely if ever seen on the arms of the United Kingdom, as unlike the 1707 Act of Union with Scotland, the 1801 Act of Union with Ireland did not provide for a separate Irish version of the royal arms.

Supporters (England): Dexter, a lion rampant gardant Or, crowned as the crest; sinister, a unicorn argent, armed, crined, and unguled Or, gorged with a royal coronet, a chain affixed thereto passing between the forelegs and reflexed over the back of the last.

Supporters (Scotland): Dexter, an unicorn argent gorged with a royal coronet, armed and chained Or holding the standard of St Andrew; Sinister, a lion guardant royally crowned Or holding the standard of St George.

Motto (England): Dieu et mon Droit

Motto (Scotland): Nemo me impune lacessit; above the crest the war-cry In defens.