Royal cypher

In modern heraldry, a royal cypher is a monogram or monogram-like device of a country's reigning sovereign, typically consisting of the initials of the monarch's name and title, sometimes interwoven and often surmounted by a crown. Such a cypher as used by an emperor or empress is called an imperial cypher.

Royal cyphers appear on some government buildings, are impressed upon royal and state documents, and are used by governmental departments. They may also appear on other governmental structures built under a particular ruler.

The use of a royal cypher in the Commonwealth realms originated in the United Kingdom, where the public use of the royal initials dates at least from the early Tudor period, and was simply the initial of the sovereign with, after Henry VIII's reign, the addition of the letter 'R' for 'Rex' or 'Regina' (Latin for "king" and "queen" respectively). The letter 'I' for 'Imperatrix' was added to Queen Victoria's monogram after she became Empress of India in 1877 (or 'Imperator' in the case of an emperor).

The initials – which had no set pattern or form of lettering laid down – were usually shown in company with the royal arms or crown as on the king's manors and palaces, such as those of Henry VIII on the gatehouse of St James's Palace. The purpose seems to have been simply to identify an individual sovereign, particularly on certain landmarks that he or she has commissioned, as the royal coat of arms in contrast was often used by successive monarchs and is therefore not distinct. The initials are furthermore used on government papers, duty stamps and similar objects, and are surmounted throughout the United Kingdom (except in Scotland) and the Commonwealth realms by a stylised version of the Tudor Crown or St Edward's Crown; in Scotland, the Crown of Scotland is used instead.

Though royal symbols (including, most notably, the coat of arms, royal standards and great seals) differ among the 15 Commonwealth realms, as they are separate monarchies, the one sovereign uses the same cypher throughout all of his or her countries. Distinction continues to be made between the personal cypher and the simpler, more workaday public initials, the former being the sovereign's own monogram and the latter simply a means of identifying a reign. Nowadays, the initials are also called the royal cypher, but, to aid clarification, the monogram is referred to as the royal cypher interlaced and reversed.

The royal cyphers have been incorporated by the Canadian Heraldic Authority into the various royal standards of Canada. The use in Canada of the reigning monarch's cypher, which is sometimes uniquely surrounded by a garland of maple leaves, is as a symbol not only of the sovereign him- or herself, but of Canada's full sovereignty.

The royal cypher is used on some Australian military uniforms.

On 26 September 2022, Buckingham Palace unveiled the cypher of the new king, Charles III, that is gradually replacing the cypher of Elizabeth II in everyday use. The design was selected by Charles himself from a series of designs prepared by the College of Arms and features the King's initial "C" intertwined with the letter "R" for Rex with "III" denoting Charles III, with a Tudor Crown above the letters. Charles's Scottish cypher uses the Crown of Scotland instead.