The Black Prince's Ruby is a large, red gemstone called a spinel. It weighs 170 carats (34 grams) and is placed in the cross pattée above the Cullinan II diamond on the front of the Imperial State Crown of the United Kingdom.

This spinel is one of the oldest gems in the Crown Jewels of the United Kingdom. Its history begins in the mid-14th century. A story from the 1760s says the stone has belonged to the English and later British monarchy since 1367, when it was given by Spanish king Peter of Castile to Edward of Woodstock, the Prince of Wales, who was known as the "Black Prince." Henry V is believed to have worn it during the Battle of Agincourt in 1415. The stone is thought to have been mined in Badakhshan, which is now part of Afghanistan. This region was the main source of large spinel gems during the Middle Ages.

Spinel

The Black Prince's Ruby weighs 170 carats (34 grams) and is about 4.3 centimeters (1 and 3/4 inches) long. In the past, all red gemstones were called rubies or "balas rubies." It was not until 1783 that scientists discovered the chemical differences between spinels and rubies. Both types of gems contain aluminium and oxygen, and both get their color from chromium. However, spinels also contain magnesium, which rubies do not have.

History

According to tradition, the Black Prince's Ruby has been traced back to the middle of the 14th century as part of the possessions of Abū Sa'īd, an Arab Muslim prince who ruled the Kingdom of Granada. At that time, the Kingdom of Castile was working to take control of Seville, and the Moorish Kingdom of Granada was being attacked by Christian forces as part of the Reconquest of the Iberian Peninsula. Abū Sa'īd faced challenges from Peter of Castile, also known as Don Pedro the Cruel or Don Pedro the Just. Historical records show that Abū Sa'īd wanted to surrender to Don Pedro, but the terms of his surrender were unclear. What is known is that Don Pedro welcomed Abū Sa'īd to Seville, likely because he wanted to gain access to his wealth. When they met, Don Pedro had Abū Sa'īd’s servants killed and may have personally killed Sa'īd. After Sa'īd’s death, the ruby was discovered and added to Don Pedro’s collection.

In 1366, Don Pedro’s illegitimate brother, Henry of Trastámara, led a rebellion against him. Unable to stop the revolt alone, Don Pedro formed an alliance with the Black Prince, the son of Edward III of England. The Black Prince fought in the Battle of Nájera and reportedly asked for the ruby in exchange for his help. Though Don Pedro had trouble giving him money, he returned to England with gemstones and two of his daughters, Dona Constanza and Dona Isabel of Castile. These daughters were later married to the Black Prince’s brothers. It is believed the ruby was taken to England at this time, though it is not mentioned in records until 1415, when it was worn by Henry V of England.

During his military campaign in France, Henry V wore a helmet decorated with precious stones, including the Black Prince’s Ruby. At the Battle of Agincourt on October 25, 1415, the French Duke of Alençon struck Henry on the head with a battleaxe, nearly killing him and damaging the helmet. However, Henry’s forces won the battle, and the ruby was saved. Later, Richard III is said to have worn the ruby in his helmet during the Battle of Bosworth in 1485, where he was killed.

In 1521, Henry VIII’s inventory listed a large "balas ruby" set in the Tudor Crown, which is believed to be the Black Prince’s Ruby. The ruby remained in the royal collection until the monarchy was temporarily ended in the 17th century. During this time, the Commonwealth took apart the royal crowns, sold the gems, and melted the gold into coins. It is unclear how the ruby returned to the Royal Collection, but in 1661, a significant ruby was purchased for the Crown Jewels for £400, which may have been the same stone. At Queen Victoria’s coronation in 1838, the ruby was part of the new Imperial State Crown, which included 3,093 gems. The ruby was clearly visible in the crown in Queen Victoria’s official portrait. The crown was redesigned in 1937 to be lighter, and a small metal plate on the back of the ruby now marks its history.

Bibliograpghy

• Bird, Rufus; Clayton, Martin, editors (2017). Charles II: Art and Power. Royal Collection Trust. ISBN 978-1-909741-44-7.
• Mears, Kenneth J.; Thurley, Simon; Murphy, Claire (1994). The Crown Jewels. Historic Royal Palaces. ASIN B000HHY1ZQ.
• Ogden, Jack (2020). "The Black Prince's Ruby: Investigating the Legend." The Journal of Gemmology. 37 (4): 360–373. Bibcode: 2020JGem…37..360O. doi: 10.15506/JoG.2020.37.4.360.