Byzantine shipwreck off Mljet – one of the most important archaeological discoveries in the Mediterranean

(Photo: Croatian Conservation Institute)

Nearly two decades of systematic underwater archaeological research around Croatia’s Mljet Island have led to the discovery of 20 previously unknown shipwrecks dating from the 2nd century BC to the 16th century.

Among them is a Byzantine shipwreck dating from the 7th or 8th century, considered one of the most important archaeological discoveries from the Byzantine period in the Mediterranean due to its exceptionally rich and rare cargo, the Croatian Conservation Institute said.

Research on the wreck began in 2015, with nine archaeological campaigns conducted to date by the Croatian Conservation Institute’s Department of Underwater Archaeology.

The most significant finds include four gold belt sets, gold buckles and belt fittings decorated with emeralds, rubies and pearls. These luxury items were used to decorate leather belts worn by high-ranking Byzantine officials and have not previously been found in the Mediterranean underwater archaeological record.

Archaeologists have also recovered gold coins depicting four emperors from the Heraclian dynasty, dating from the end of the 7th century. The coins have helped establish a more precise timeframe for the ship’s sinking.

Particularly significant is a gold ring depicting an emperor from the Heraclian dynasty. Such a ring could have belonged only to a person from the highest levels of the Byzantine state or military, authorised to seal imperial documents.

(Photo: Croatian Conservation Institute)

It may have been a diplomatic gift or the personal possession of a senior Byzantine official, the Croatian Conservation Institute said.

The discovery provides important clues about the status of the people aboard the ship and the significance of its cargo.

The vessel also carried a substantial commercial load, including amphorae, trade scales, ivory tokens and ceramic vessels such as bowls, jugs and plates.

Mljet lies along an important maritime route linking the eastern and western Mediterranean. Archaeologists believe the ship may have sunk while attempting to seek shelter in Polače Bay, whose protected position and late antique palace made it a refuge for ships during bad weather.

The research is led by underwater archaeologists Igor Miholjek and Pavle Dugonjić of the Croatian Conservation Institute. The project is supported by divers from the Intervention Police Command of the Croatian Ministry of the Interior, Aquatica Mljet diving centre and NavArchos, led by Dr Anton Divić.

(Photo: Croatian Conservation Institute)

This year, the project is being carried out in cooperation with archaeologists from Stanford University, led by Professor Justin Leidwanger, who are analysing the ship’s cargo, particularly the amphorae and ceramics.

Long-standing partners Professor Falko Daim and Dr Levante Samu are examining the production technology and decoration of the gold belt sets, while Dr Željko Demo is analysing the coins.

The continuing research is expected to provide further insight into the ship, its passengers and the trade and political networks that connected the Byzantine world with the Adriatic and the wider Mediterranean more than 1,300 years ago.