A 2,000-year-old sapphire ring, often attributed to Roman Emperor Caligula, features a delicate portrait engraved into the stone, widely believed to be his fourth and final wife, Caesonia. Crafting a ring from a single piece of sapphire was an immense technical feat in antiquity.
The Material: It is a hololith, meaning the entire ring (both the stone and the band) was carved out of a single piece of sky-blue sapphire.
The Engraving: The bezel features the profile of a woman, which historians and gem collectors associate with Caligula's empress, Milonia Caesonia.
Current Status: The ring is part of the legendary Marlborough Gems collection. It previously surfaced at an auction through the royal jewelers Wartski.
Provenience & Skepticism:
While popular tradition links the ring to Caligula's extravagant reign (37–41 AD), many historians note that it is extremely difficult to verify ancient provenance. The earliest documented history of the ring traces back only to the 17th-century collection of Thomas Howard, the Earl of Arundel. Some art historians debate its ancient origins, suggesting it may have been crafted during the Renaissance.