The tradition of exchanging rings to symbolize an engagement has deep historical roots, tracing back to ancient Rome. Noble families used iron bands known as annuli pronubi to signify marriage agreements. Over time, the significance of these rings evolved, particularly with the introduction of diamonds in the medieval period due to their durability and association with steadfastness. However, British royalty often diverged from this trend, opting for sapphires, emeralds, and rubies instead. This article explores over 150 years of royal betrothals and the gemstones chosen to mark them.

In ancient Rome, noble families utilized iron rings to represent matrimonial commitments. According to Pliny the Elder, these rings were worn on the fourth finger of the left hand because it was believed to contain a vein leading directly to the heart. Centuries later, during the medieval era, diamonds became favored tokens of engagement due to their resilience and connection to constancy. One notable instance occurred in 1476 when Mary, Duchess of Burgundy, received a diamond ring shaped into a sparkling "M" from her groom-to-be, Roman Emperor Maximilian of Austria. This event helped cement diamonds as the preferred choice for aristocratic weddings.

Despite this diamond-centric tradition, many members of the British royal family have opted for alternative gems. Queen Victoria's engagement ring, presented by Prince Albert in 1839, featured an intricate ouroboros design—a coiled snake symbolizing eternal love. Its head was adorned with an emerald, representing her birthstone, while its eyes were crafted from rubies, signifying passion. This unique choice sparked a trend, inspiring numerous snake rings from that era to incorporate turquoise stones, which were thought to evoke the enduring nature of romance.

Throughout history, royal engagements have been marked by diverse gemstones, each carrying profound meaning. From the ancient belief in the vena amoris to the modern-day preferences of the British monarchy, these rings serve as enduring symbols of love and commitment. As we reflect on more than a century and a half of royal betrothals, it becomes evident that the choice of gemstone reflects not only personal taste but also cultural and historical influences.