An unprecedented gold treasure was discovered in the depths of the sea – and revealed a 1,300-year-old secret

More than 1,300 years after a ship sank off the coast of Croatia, the findings salvaged from it are beginning to reveal who might have been sailing on board. The Croatian Conservation Institute presented this summer the results of years of underwater excavations of a ship dating back to the late 7th or early 8th century AD. Among the remains, more than 600 grams of gold, Byzantine coins, and luxury jewelry set with gemstones were found — findings that led researchers to estimate that a wealthy and influential person, along with their entourage, was on board.

The remains of the ship were discovered more than a decade ago on the seabed near the island of Mljet in Croatia. Since 2015, systematic underwater excavations have been conducted at the site, and now the findings collected over the years of work have been officially presented. In the published photos, one can see an impressive collection of jewelry. Among other things, buckles decorated with rubies, emeralds, and pearls were found, alongside a gold signet ring.

It was the ring that provided researchers with a significant clue regarding the possible identity of one of the ship's passengers. Pavle Dugonjić, head of the Department of Underwater Archaeology at the Croatian Conservation Institute, stated that a ring of this type "certainly would not have been worn by just anyone." The combination of the signet ring and the luxury jewelry led to the assessment that a person of high social status was on the ship, and perhaps an entourage that accompanied them.

Alongside the jewelry, gold coins issued during the time of four emperors of the Heraclian dynasty, which ruled the Byzantine Empire during the 7th and 8th centuries, were also found. In total, more than 600 grams of gold were found on the ship — an amount that, according to the researchers, makes the finding exceptional even in relation to other ancient ships discovered in the area.

Igor Miholjek, head of research at the Croatian Conservation Institute, noted: "This is an impressive amount of gold." According to him, it is "the largest amount ever found on a shipwreck in the entire Mediterranean," and it weighs more than 600 grams after cleaning and restoration.

Researchers still do not know for sure to whom the jewelry belonged or who wore the signet ring, and therefore there is no identification of that passenger at this stage. However, the nature of the items provides a clue that at least one of the people on board was not an ordinary passenger. The jewelry set with precious stones, the gold, and the signet ring point to significant wealth and status. The possibility that an influential person and their entourage were sailing on the ship adds a new layer to the mystery: who were the people on board, where were they headed, and what led to its sinking about 1,300 years ago.

For archaeologists, the importance of the discovery is not limited to the gold. Prof. Justin Leidwanger from Stanford University defined the remains as "the most important shipwreck of its time." According to him, the site may provide rare information about the period when the late Roman world gradually changed and became the world of the Middle Ages. "If you are studying the end of the late Roman Empire and the transition to the medieval world, this is a critical site for us to understand how the Mediterranean was connected through its sea routes, how it split, and how the empire disintegrated," he explained.

The Byzantine Empire was the eastern continuation of the Roman Empire and existed until the fall of Constantinople in 1453. At its peak, it controlled vast territories around the eastern Mediterranean. The ship discovered near Mljet dates back to a much earlier period — the late 7th or early 8th century — and therefore it may provide researchers with a glimpse into the trade, maritime traffic, and people who crossed the Mediterranean during a time of great changes.