A joint team from the European Institute of Underwater Archaeology (IEASM) and Egypt’s Ministry of Tourism and Antiquities discovered the artifact among the ruins of a submerged palace on the island of Antillodos in the Mediterranean Sea.

According to the IEASM, the find marks the first time its researchers have discovered a signet ring engraved with an image of the Lighthouse of Alexandria.

A signet ring with a possible lighthouse engraving

IEASM representatives said the image on the bronze ring resembles depictions of lighthouses found on coins dating to the second century. Although the engraving is worn, researchers believe it most likely represents the famous lighthouse built on the island of Pharos.

Signet rings were used to create impressions in soft materials such as clay or wax. The discovery of the ring in the palace ruins may indicate that the building had administrative functions connected to the lighthouse, IEASM representatives said.

“The discovery of the Ring Seal is all the more important because it was excavated in a legendary palace on the island of Antillodos, once a center of power,” Frank Goddio, president of IEASM, said in an emailed statement.

The palace and the Lighthouse of Alexandria

The palace was used by Egyptian pharaohs who ruled during the Ptolemaic period, which lasted from 304 B.C. to 30 B.C. The era followed the conquests of Alexander the Great and saw Alexandria become a major center of power and culture.

The Lighthouse of Alexandria was built on Pharos around 280 B.C. and stood more than 100 meters high. Ancient writers, including Pliny the Elder, regarded it as one of the wonders of the ancient world.

The lighthouse remained in use into the Middle Ages before earthquakes, erosion and other damage caused it to collapse and sink into the sea. Although it was renovated over time, it may have featured a statue of Zeus at its summit and an oil lamp to guide sailors.

Experts examine the ring’s unusual details

Doris Behrens-Abouseif, emeritus professor of art history and archaeology at the University of London, was not part of the research team but has written about lighthouses.

“There are thousands of Alexandria coins that show similar depictions of lighthouses,” she told Live Science by email. She noted that the coins date from the Ptolemaic or Roman periods, spanning approximately 29 B.C. to A.D. 395.

Behrens-Abouseif said she did not know enough about the newly discovered ring to determine whether it is the only ring bearing this image.

Other scholars who spoke with Live Science also said they believe the engraving depicts a lighthouse. Two researchers suggested that an asymmetrical detail at the top may represent smoke rising from a lamp.

“The most interesting aspect of the new gem-engraved signet ring is the asymmetrical feature of the apex,” which “may depict a plume of smoke from an oil lamp in the crowning figure’s hand,” Andrew Chugg, an independent researcher and author of Pharos Lighthouse in Alexandria: The Second Sun and the Seventh Wonder of Antiquity (Routledge, 2024), said in an email.

Margaret Miles, professor emerita of art history and classics at the University of California, Irvine, also noticed the possible smoke plume.

“This ring may have been used as a signet ring by a merchant in Alexandria who may have used that profile of the lighthouse to identify his position in Alexandria,” Miles said in an email. “The lighthouse was so famous that it became a symbol of the city.”

Underwater research continues off Alexandria

Recent research off the coast of Alexandria has uncovered 22 giant blocks, helping researchers investigate the lighthouse’s construction and appearance. Archaeologists are also working to digitally restore the ancient landmark.

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