The 7th century Yeni Kapi 11 wreck in Turkey

Historical Significance of the Harbor of Theodosius

In 2004, the Istanbul Archaeological Museums, in collaboration with the Marmaray Project, began excavations in the Yeni Kapi neighborhood of historic Constantinople. The research quickly revealed the remains of the Theodosian Harbor, dating back to around 390 AD. This harbor, the largest of the city's four main commercial ports from the 4th to the 7th century, was crucial for the economic and urban development of Constantinople.

The Theodosian Harbor facilitated the import of essential goods necessary for the rapid expansion of the city during the Byzantine period. Among these materials were timber and marble, mainly from the island of Marmara. These construction materials were vital for the large-scale building projects required for the rapid urban development of Constantinople, as the city established itself as the capital of the Byzantine Empire.

Representation of the Habror of Theodosius, Sea of Marmara.

Despite its initial significance as the largest and most central harbor of Constantinople, the extent of the operational area of the Theodosian Harbor gradually diminished over time. This is evidenced by the dispersion and dating of shipwrecks in the area of Yeni Kapi, where a concentration of later shipwrecks was observed in the eastern part of the harbor. Historical references suggest that this decline in usage may be correlated with the drastic reduction in the city's population in the 7th century, due to the loss of significant territories of the Byzantine Empire to Arab conquests, such as the occupation of Tunisia in 696 AD. These developments reduced the need for large port facilities, affecting the significance and usage of the harbor.

The above observations are also reflected in the shipwrecks discovered within the harbor. In total, 37 ships were identified at a terrestrial point of the installation, which had fallen into disuse and were abandoned to sink over time. Of these, 31 were primarily - or even exclusively - sail-powered and are described in the literature as "round ships". Primarily of commercial nature, they were designed for maximum capacity and flexibility. They featured a single mast with a lateen sail and were steered with a pair of oars.

The excavation of the Yeni Kapi shipwrecks. Photo: Bekir Köşker.

The plethora of findings resulting from the excavation provided researchers with valuable insights into maritime trade, shipbuilding technology, and the way of life in the Byzantine capital during a significant period of Mediterranean history. Among the various vessels identified during the excavations, the ships Yeni Kapi 11 and Yeni Kapi 14 stand out, which were excavated and documented under the supervision of Cemal Pulak.

The Shipbuilding of Yeni Kapi 11

The excavation program at the Yeni Kapi harbor began with the mapping and dismantling of the ships for their transportation. The hulls of the ships were remarkably well preserved, possibly due to direct coverage by sand after their sinking. One of the most significant discoveries was the replacement of the technique of mortise-and-tenon joints with the method of connecting the ends with treenails in ships from the 8th century onwards. This suggests the possible application of Byzantine shipbuilding technology, at least at a regional level.

Wreck of Yeni Kapi 11 in situ, with removal of the upper level of wood, 2008. View from the stern. (Photo: O. Koyagasioglu/INA).

The Yeni Kapi 11 was discovered in 2006 near the western edges of the harbor, in one of the lowest areas of the site. Floods from groundwater and the thick, muddy sediments in which the wreck was located often caused delays in the research. Damage from shipworms (Teredo navalis) observed on the ship's hull, as well as the distortion and displacement of certain wooden parts, indicate that the vessel did not sink suddenly due to a catastrophic event but was abandoned in the western corner of the Theodosian Harbor, which had already gradually ceased to be used.

Sketch of the Yeni Kapi 11 on the seabed. (Ingram 2018)

After thorough study of the findings and radiocarbon analysis, the wreck was dated to the first half of the 7th century. The ship's timber was exceptionally preserved due to its sinking in anaerobic sediments of the harbor. The right side up to the curvature of the floor timbers and the left side up to the second wale were preserved. Construction materials mainly included Turkish pine (Pinus brutia) for the main frame and Turkish oak (Quercus cerris) for the keel, to increase durability. Analysis of the remains led to the conclusion that the ship was constructed using both the 'shell-first' and 'skeleton-first' techniques, exhibiting many similarities with other wrecks of the same period, such as the Yassi Ada 1.

Representation of the keel, sternpost, and hook scarf joint. (Ingram 2018)

The three individual parts that the keel was made of, were secured together through mortise-and-tenon joints, reinforced with iron bolts. The stem and sternpost were also fastened with the same bolts, while a pair of closely spaced knees provided additional longitudinal support to the hull. The futtocks, up to the second strake below the first wale, were assembled using the method of joining the ends with hooks and horn timber, avoiding the use of treenails.

It is worth noting that the planks of the hull exhibited traces of caulking, consisting of a mixture of grass fibers and a resinous sealing material – possibly from pine. This mixture was also used on the interior and exterior surfaces of the hull. Additionally, based on a fragment found near the wreck, researchers noted that some frames of the ship had mortises and were possibly secured onto the frames with elongated iron nails.

Representation of the frames and futtocks of Yeni Kapi 11. (Ingram 2018)

According to the researchers, the ship Yeni Kapi 11 reflects the owner's austerity, which is reflected in both the choice of construction materials and the frequency of repairs it underwent. Specifically, the recycled section of wood from the keel reused as a transom, the closely spaced iron nails placed on the frames, and the parallel repairs or replacements of parts of the hull evidence the intention to conserve resources, using less costly or readily available recycled materials.

As for the shipbuilding technique, the arrangement of the ship's frame followed the established Mediterranean pattern of the time, which included the alternating futtocks and floors, providing lateral support to the hull. However, each individual futtock or floor was fastened to the keel and the ship's frames with long iron nails, while the frames themselves were also secured to the planking with shorter iron nails. The absence of edge to edge connections in the rows of planks below the first wale, in combination with the above, are some of the various indications supporting the hypothesis that these planks were fastened onto pre-installed frames at this stage of the ship's construction.

The discovery of Yeni Kapi 11 sheds light on 7th-century shipbuilding and economy. It reveals a blend of old and new techniques, showing the continuous evolution of shipbuilding. Additionally, the reuse of materials and repairs reflect ancient mariners' efforts to extend their ships' economic lifespan. This study also enhances our understanding of ancient shipyards and their connection to the socio-economic conditions of the time.

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