Portrait of Queen Victoria in her coronation robes by George Hayter, between circa 1838 and circa 1840 | Source: Wikimedia Commons

When we think of the grand jewels that fill the treasure rooms of monarchs and royal dynasties, the Black Prince's Ruby is one that captures both the imagination and admiration of historians, jewelers, and lovers of all things jewelry. You might have heard of it, resting magnificently at the center of the British Imperial State Crown, glowing with a deep red hue that has witnessed centuries of intrigue, war, and royal drama. But here's the thing—despite its name, this gem isn't a ruby at all! Let's journey through time, where this legendary gemstone becomes entwined with tales of bloodshed, mystery, and opulence.

Imperial State Crown of the United Kingdom | Source: Wikimedia Commons

Not a Ruby, But Still Royal: What is the Black Prince's Ruby?

The Black Prince's Ruby is not actually a ruby. Instead, it's a spinel, a gemstone often mistaken for ruby in the Middle Ages. Spinel, especially when it's a vivid red like this one, closely resembles ruby, and for centuries, people were unable to tell the difference. This widespread misidentification occured because gemology, as we know it today, didn't exist back then. Scientific methods like testing chemical composition and analyzing crystal structures were unheard of. Jewelers of the past relied primarily on appearance, and under varying light conditions, it's easy to see how two gemstones with similar colors could be mistaken for one another. While rubies are made of corundum, spinel has a completely different chemical structure—yet to the royal courts, that didn’t matter. To them, this gleaming red stone was as royal as it gets.

And boy, did it live up to its reputation! Spinel or ruby, what really makes the Black Prince’s Ruby stand out isn’t just its color or sparkle. It’s the incredible history attached to it.

The 'Ruby's' Early History

To truly appreciate the Black Prince's Ruby, we need to start in 14th-century Spain. The year was 1366, and Spain was embroiled in a chaotic civil war. Two half-brothers, Pedro the Cruel and Henry of Trastámara, were locked in a fierce battle for the throne of Castile. The ruby—let’s keep calling it a ruby for ease—was owned by Pedro, who was not-so-lovingly nicknamed "the Cruel." His reign was marked by violence and tyranny, and he wasn’t exactly a favorite among his people.

Pedro needed allies to keep his throne, and that's where the Black Prince, Edward of Woodstock, came in. Edward, known as the Black Prince for the color of his armor (and perhaps his fearsome reputation), was a warrior prince from England, eager to make his mark on the world. In exchange for military aid, Pedro gifted Edward this massive red gem—a symbol of power and prestige.

Full page miniature of Edward of Woodstock, the Black Prince, of the Order of the Garter, wearing a blue Garter mantle over plate armour and surcoat displaying his arms. A framed tablet displays painted arms of successors in his Garter stall at St. George's Chapel, Windsor. Circa 1440-1450. | Source: Wikimedia Commons

Little did anyone know, the Black Prince's Ruby was already stained with blood. Legend has it that Pedro had stolen the stone from the Moorish King of Granada after personally killing him. Whether or not the tale is true, the ruby certainly seems to have a knack for attracting violence and chaos.

The Black Prince's Ruby in English Royal Hands

So, Edward took the ruby back to England, and it became a treasured piece in the English royal collection. This is where things get interesting—because the Black Prince’s Ruby didn’t just sit in a royal jewelry box collecting dust. No, it was front and center during some of the most pivotal moments in English history.

For starters, Edward didn’t get to enjoy the ruby for long. He died before he could become king, but the ruby stayed within the royal family. Fast forward to the 15th century, and the ruby found itself in the hands of Henry V, one of England’s most legendary kings. It was Henry V who, against all odds, led his troops to victory at the Battle of Agincourt in 1415—one of the most famous battles of the Hundred Years’ War against France.

Battle of Agincourt, 1415. King Henry V of England at the Battle of Agincourt, France, 25 October 1415. Line engraving, 19th century. | Source: Wikimedia Commons

Henry wore the Black Prince’s Ruby in his battle helmet. Can you imagine that? Charging into battle with a giant red gem embedded in your crown! The sheer audacity of it speaks volumes about the symbolism of the ruby—it was a sign of indomitable royal power. The story goes that during the heat of battle, Henry was struck in the head with an axe, but miraculously, the ruby remained intact, as did Henry. The gem seemed to have a protective aura, further cementing its reputation as a powerful royal talisman.

The Stone Survives—and Thrives

The ruby's journey didn't stop there. Over the centuries, it passed from one English monarch to another, each time growing in symbolic power. During the turbulent times of the War of the Roses, the stone remained a steady presence, although it witnessed more than its fair share of betrayals and beheadings.

Then came the 17th century and the reign of Charles I, a monarch whose rule ended in disaster. 

Charles I (1600-1649) with M. de St Antoine by Anthony van Dyck, 1633 | Source: Wikimedia Commons

He lost his head—literally—but the Black Prince’s Ruby survived, passed down to his son, Charles II. While many of the Crown Jewels were destroyed or sold off during the English Civil War, the Black Prince’s Ruby was one of the treasures that made it through. It became an enduring symbol of the British monarchy itself: resilient, powerful, and seemingly indestructible.

But how did this medieval gem end up in the center of the British crown?

Center Stage in the Crown Jewels

By the 19th century, the Black Prince’s Ruby was firmly embedded into the Imperial State Crown (pictured above), one of the most iconic pieces of the British Crown Jewels. If you’ve ever watched a British royal coronation, you’ve likely seen this magnificent crown. It’s the crown used for state openings of Parliament, and it’s worn by British monarchs during key ceremonial moments.

At the center of the crown, among diamonds and other glittering gems, sits the Black Prince’s Ruby, a jewel that has seen more than 600 years of royal history unfold. From wars to coronations, coups to victories, this gem has been there through it all, watching silently as monarchs come and go.

Platinum AGL 8.92ct Unheated Tanzanian Red Spinel and Diamond Ring | Walton's Jewelry

How Misidentified Gems Shaped Jewelry Trends

So, what’s the takeaway from this long, glittering history? These centuries of mistaken identities didn't just affect the gem market—they continue to influence the entire jewelry industry today. For much of history, people valued gems based on their appearance, color, and the myths attached to them.

In today's world, spinel is finally getting the recognition it deserves as a gem in its own right. Jewelers and collectors now appreciate spinel for its unique beauty and rarity, and it has become a highly sought-after gem, especially in its vivid red color. Its misidentification didn't diminish its status—on the contrary, it enhanced it!

Today, spinel, emerald, amethyst, and countless other gemstones once misidentified continue to captivate us—not just for their sparkle, but for the unique stories they tell. The world of gemstones is as complex and intriguing as any novel, filled with twists, turns, and, yes, the occasional case of mistaken identity.