Object

The Imperial State Crown of the United Kingdom is the working state crown worn by the sovereign at the State Opening of Parliament and at other state occasions of comparable formality. The current frame was made in 1937 by Garrard for the coronation of George VI, replacing the earlier Imperial State Crown of Queen Victoria of 1838. The historic gemstones were transferred from the Victorian frame, so that despite the relatively recent date of the metalwork, the principal stones have been in continuous use for centuries.

The crown is held in the Tower of London as part of the Crown Jewels of the United Kingdom and is on permanent public display when not in use.

Construction

The frame is gold and silver, set with a total of 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls and 5 rubies, in a closed crown form comprising a circlet, four arches meeting at the top with a small orb and cross above. The cross is set with the Saint Edward's Sapphire, an octagonal sapphire from the ring of King Edward the Confessor, who reigned in the eleventh century. This sapphire is one of the oldest individually identifiable gemstones in any working European regalia.

The principal stones

The Cullinan II diamond, also called the Second Star of Africa, is mounted at the front of the circlet immediately below the Black Prince's Ruby. It weighs three hundred and seventeen and four tenths carats and is the second-largest of the nine major polished stones cut from the original Cullinan rough of three thousand one hundred and six and seventy five hundredths carats found at the Premier Mine in South Africa in 1905.

The Black Prince's Ruby, set above the Cullinan II in the centre of the cross over the band, is in fact a red spinel rather than a ruby, weighing approximately one hundred and seventy carats. It came into English possession in the fourteenth century when Pedro the Cruel of Castile presented it to Edward, the Black Prince, in 1367 in payment for military assistance. The stone has been worn by every English and British sovereign at coronation since, with documented appearances at the coronations of Henry V (with the stone reputedly worn in his helmet at Agincourt), Henry VIII, Elizabeth I, and the Stuart and Hanoverian sovereigns.

The Stuart Sapphire, a one hundred and four carat oval cabochon, sits at the rear of the band. It is associated with the Stuart dynasty and was returned to British state possession after passing through the exiled Stuart line.

The Saint Edward's Sapphire, set in the cross at the top of the crown, is reputedly from the ring of King Edward the Confessor and was reset into successive coronation pieces from the medieval period onward. It is the oldest individually traceable stone in the crown.

The Queen Elizabeth Pearls, a set of four large pearls, hang below the arches at the rear and are associated with Queen Elizabeth I, who reportedly received them from Catherine de Medici.

Use and ceremony

The Imperial State Crown is the working crown of the British monarchy, worn at the State Opening of Parliament each year (with brief exceptions for sovereigns under bereavement or for other ceremonial reasons), at coronations after the actual coronation moment when Saint Edward's Crown is replaced by the Imperial State Crown for the procession out of Westminster Abbey, and at certain other state occasions. The crown's working role distinguishes it from Saint Edward's Crown, which is reserved for the coronation moment itself, and from the various royal crowns and regalia held in the Tower for ceremonial display only.

The crown weighs approximately one and six tenths kilograms, lighter than Saint Edward's Crown at two and three tenths kilograms but still significant for prolonged wear. King Charles III, like his predecessors, has worn the Imperial State Crown at the State Opening of Parliament and at other formal occasions. The crown's weight and the sovereign's neck strain have been a subject of public commentary by Queen Elizabeth II, who in 2018 noted in a televised interview the practical difficulty of reading from a paper while wearing it.

The Cullinan stones in context

The Cullinan I, also called the Great Star of Africa, weighs five hundred and thirty and two tenths carats and is mounted in the Sovereign's Sceptre with Cross, not in the Imperial State Crown. It is the largest polished colourless diamond in the world. The Cullinan II in the Imperial State Crown is the second largest. The pair was cut from the original Cullinan rough by Joseph Asscher of the Asscher Diamond Company in Amsterdam in 1908, with the cutting taking eight months and producing nine major polished stones plus ninety-six smaller ones.

Conservation and security

The crown is in continuous conservation custody at the Tower of London, with regular inspection and maintenance by the Crown Jeweller, currently the firm of Aldridge in succession to Garrard. The crown is moved under exceptional security between the Tower and Westminster for state occasions and returned immediately. The crown's gemstones have not been replaced or removed since the 1937 reframing, and the Cullinan II in particular has been continuously in this setting since 1937.

The Cullinan diamonds, including the Cullinan II in the Imperial State Crown, have become the subject of restitution discussion since the 2000s. The South African government and various civil-society organisations have raised the question of whether the original Cullinan rough, presented to Edward VII by the Transvaal Colony in 1907, should be returned. The British government's position has been that the stones were a sovereign gift legally received, and the matter has not progressed to formal diplomatic action.

Place in the trade canon

For the working trade, the Imperial State Crown is significant as the most-photographed working crown in continuous use globally, as the principal modern reference point for late-nineteenth and early-twentieth century coronation jewellery construction practice, and as a documented reference set of major historical stones whose provenance and gemmological identity have been extensively studied. The reattribution of the Black Prince's Ruby from ruby to spinel, completed gemmologically in the late twentieth century, is a foundational reference case for understanding the broader category of historical stones reattributed across European royal collections.