A rich underwater site was discovered in 2006 in the local waters of the Island of Mljet, near the St. Paul Shallows. Some 40 metres below sea level, exceptionally preserved remains of an early-modern shipwreck were discovered, among them eight bronze cannons and scattered fragments of ceramic ware, glass and metal artefacts. Surveys revealed they came from a 16th-century merchant ship transporting luxury cargo on a route between the merchant ports of the Eastern Mediterranean and Venice. Next year, the employees of the Department for Underwater Archaeology of the Croatian Conservation Institute initiated the first of five campaigns so far, in order to complete the picture of the circumstances of the shipwreck, gain insights into the production, the economic context, trade sea routes and perils of sea fare in the turbulent times of the cinquecento.

Early modern shipwreck

At the bottom of the sea, not far off the Island of Mljet, a rich archaeological site was discovered, with the remains of a 16th-century merchant shipwreck. As the site had until then been unknown, in addition to the discovery of numerous finds, the exploration of the shipwreck provided a valuable experience for the archaeologists who had the chance to investigate the intact site for a number of years.


The Shallows of St. Paul are located on the southern side of the Island of Mljet, several hundred metres off the coast. The shallows are fully exposed to southern winds and waves. A little further west are the Islet of Preč and the Dugi Rat Cape with its cove, which both make a natural shelter and anchorage when travelling along the southern coast of the island, from the area of the Mljet Lakes to the Saplunara Cove. The shallows peek through the sea by only a few centimetres, which makes them barely visible and during bad weather, a perilous trap on the way to a safe haven.

The site was discovered in 2006 by the divers of the Medveščak-Sava Club during a divers’ gathering organized in the Island of Mljet. At the depth between 40 and 46 metres they discovered six bronze cannons with fragments of pottery, glass and metal objects scattered around them. Everything pointed to a new, intact archaeological site, so the discovery was immediately reported to the institutions in charge. An expert inspection was carried out by the Service for Cultural Heritage Protection Inspection Activities of the Ministry of Culture, the Dubrovnik Port Authority and the Department for Underwater Archaeology of the Croatian Conservation Institute. The site was photo-documented and several objects were recovered for inspection. These were revealed to be remains of a 16th-century merchant ship which transported a rich cargo on the route between the merchant ports of the Eastern Mediterranean and Venice. In order to protect and defend itself from the enemy at sea, the ship was armed with several bronze cannons.

The finds

Archaeologists of the Croatian Conservation Institute initiated an archaeological survey of the site in 2007. So far, five campaigns have been undertaken, with the last one finished in 2011. The goal of the first phase of exploration was to draw up a complete graphic and photo documentation of the pre-existing condition at the sea bottom. Given the exceptional value of the bronze cannons and other preserved artefacts, it was decided that all movable material should be documented and recovered from the sea, in order to prevent a devastation of the site.

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In the course of the first three campaigns eight cannons were recovered. Seven of those were pedreros – the cannons with a mascolo, a loading device placed at the rear end. This type of cannon was made to fire stone projectiles. An esmeril was also found – a type of cannon constructed to fire iron projectiles, loaded through the barrel from the front side. Two almost identical pedreros are larger-calibre, while the remaining five are smaller-calibre. All seven pedreros were made from a combination of two metals – the barrel was cast in bronze, and the breech was made of iron. Unfortunately, the majority of breeches were heavily corroded so they were not recovered. Only one pedrero (no. 8) was found with the breech attached and a portion of an iron fork that was used to embed the cannon into the railing of the ship.

Apart from the pedreros, a number of matching-calibre stone balls were found at the site. The barrels of the two larger pedreros are 1.46 metre long, with moulded and decorated muzzles of a 106-millimetre calibre. Both pedreros are decorated with Renaissance relief motifs. Tips of the barrels are decorated in stylized tendrils with arrow-like endings which connect the motifs of a lion’s head, an empty coat of arms richly bordered with bands and the vegetable ornamentation. Above the central reinforce ring of the barrel there are decorations in the form of acanthus leafs and five-petal flowers. All the recovered pedreros have numbers incised to indicate their weight in librae. However, the weight in librae varied depending on the foundry and the country where the cannon was cast. It was revealed that the weights of the cannons found off Mljet closely match the weight of the Venetian (heavy) libra.

The recovered esmeril is 1.20 metre long, with the breech measuring 5.3 centimetres. The barrel measures 9.9 centimetres in diameter at the muzzle, with a 5-centimetre calibre. It is polygonal in section, with twelve edges and two cylindrical protrusions in the central portion of the cannon. The barrel has neither the characteristic relief decorations nor incisions which could identify its origin. Interestingly, during the conservation process, a corroded iron ball was found inside the barrel, measuring 4 centimetres in diameter. According to available archaeological sources, it was common in this period to keep the cannons loaded while sailing.

After analyzing various archaeological finds from the site, the shipwreck was dated to the second half of the 16th century. It was determined that most of the cannons had been made during that century, that most of the pedreros came from Venetian foundries, while the origin of the esmeril remains unknown.

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A number of metal objects were recovered from the site, among them a large bucket ornate with strips and decorative rivets, a bronze saucer and a richly decorated conical vessel, fragments of a candlestick and a tin jug. Another very valuable find is a large ceramic bowl found near the bucket. The bowl carries an engraved depiction of a mandolin player in a flower garden with a wattle fence. Bowls such as this, with allegorical depictions of virtues, were given as engagement or wedding gifts and were considered a luxury ware.

Most of the finds recovered from the site are ceramic ware. It was determined that a portion of the pottery is a product of the Venetian 16th-century workshops. Another group belonged to the Oriental, very luxurious and richly decorated ceramics or, on the other hand, simple Oriental cutlery. The luxury Oriental ceramics, judging by its quality of execution and the rich brightly-coloured ornamentation, could be attributed to the renowned pottery workshops of the Turkish town of Iznik. Their unique style or decoration was influenced by the local Oriental red engobe pottery with painted rosettes or leafs coated in green, blue or amber-colour glaze. Another influence came from the Turkish tradition of making luxury silverware as well as from the Chinese porcelain production, especially from the times of the Yuan (1260-1368) and the Ming (1368-1644) Dynasties. The Iznik pottery is characterized by decorations done in cobalt-blue and ultramarine colour on white background, and the frequent use of black, green and red colour. In most cases the edges of plates are undulating and the painted motifs mostly consist of stylized waves and sea foam, blooming lotuses, lilies and other flowers, foliage and vines.

At one location within the site, a dozen large luxury Iznik plates were found folded one over the other, with several smaller, also richly decorated plates and about ten smaller bowls folded one over the other. This confirmed our assumption that the ship was carrying Oriental merchandise intended for the Western market. Nearby, fragments were found of beautifully decorated jugs and bowls of the same origin. Among the particularly interesting objects we can single out a small bronze ship’s bell with the year MDLXVII (1567) set off in relief, which confirms the assumption that the shipwreck took place in the second half of the 16th century. Additional confirmation for such a dating comes from the dozens of silver coins that were recovered, among them two thalers attached to several dozens of akçe. According to a depiction and an inscription on the obverse, the thalers were minted in 1559, during the rule of the sons of John Frederick I, Prince of Saxony. On the obverse there is a bust of the Prince in armour, holding a scepter in his hand, the letters on the outer inscription field: MO:NO-FRATR-V(-)M:DVC(V)-:SAXO(N)., and four coats of arms on each side. At this point, some encrusted akçe are still attached to the reverse side, but based analogies the reverse should include two juxtaposed busts and an inscription: LANTG:-THVRI:-ET:MAR-:MISN:. The silver Ottoman coins, akçe, were minted throughout the Ottoman Empire from the 15th to the 17th century. A detailed analysis of the money found will provide us with further guidelines for dating the shipwreck with complete accuracy.

Other finds include a two-sided horn comb, several pine cones (pinus pinea), animal bones and pieces of cutlery, a large grindstone and several dozens of stone cannonballs. One of the balls is much larger than the others, measuring 16 cm in diameter, which indicates that not all the cannons have yet been found. A small lead gun bullet recovered also indicates that, apart from the cannons, the ship had also been armed with rifles, arquebuses and muskets.

The ship’s construction

In another part of the site, southeast of the area with the cannons, on a gentle sandy slope with no significant concentration of immovable material, a wooden construction of the ship was discovered. During the investigation, a special attention was devoted to preserving the wood in the condition in which it had been found.

In order to compile the complete graphic and photo documentation of the ship’s construction, in May 2010 cooperation was initiated between the Croatian Conservation Institute and the Department of Antiquity and the Middle East of the University Ca’Foscari in Venice, headed by Prof. Carlo Beltrame. The cooperation continued into 2011, along with the documentation of the ship’s wooden construction. So far, fifteen hull planks and six ribs have been documented and recorded using a photogrammetric method. A seventh rib was found while cleaning the vessel’s construction, along with some other parts of the planking. The entire construction was photo-documented, including each detail in various portions of the construction. An air parachute was used to recover the futtock no. 1 and the hull plank no. 15. The hull plank no. 15 was immediately returned to its place after a sample of the wood was taken for dendrochronological analysis. The futtock was transferred to our base where it was photographed in detail and documented with a 1:1 ratio drawing before being returned to its place. Results of the investigation indicated that the characteristic joints of two parts of the futtock were used in Venetian shipbuilding. Investigations of the hull revealed that the vessel had no keel, but instead used a so-called inner keel, which was located on the inner side of the planking. On both sides of the inner keel, on the ribs, limbers for bilge water were found, which pointed out with certainty that this was the longitudinal axis of the ship. Furthermore, a base for the mast was found within the wooden construction, in the form of a cube with lateral reinforcements. The hull of the ship had double planking, and in between the two layers sheet metal was found in places. It is unclear whether the sheet metal once covered the entire planking of the vessel, as this kind of construction has not yet been recorded in the 16th century. If so, this would be a remarkable example.

Although early-modern shipwrecks constitute no rarity in the Croatian underwater, only rarely do they remain intact until the present day. Even more rare is their systematic exploration. The surveys carried out from 2007 to 2011 at the site of St. Paul Shallows off the Island of Mljet constitute only a segment of the systematic protection investigation. Apart from the usual graphic, photo and video documentation of the site and the finds, this investigation is an attempt to gain a more complete insight into the circumstances of the shipwreck, reach information on the production, the economic context, sea trade routes and perils of sailing in the turbulent times of the 16th, 17th and 18th centuries.

Authors: Vesna Zmaić, Igor Miholjek, Igor Mihajlović


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