A new study of iron helmets found off the coast of Spain in 1990 has revealed that they are not Roman as previously thought; they date to the late 14th/early 15th century. Now that they have been properly dated, the quantity make it the largest hoard of medieval helmets ever found in the western Mediterranean.The helmets were discovered off the coast of Benicarl, eastern Spain, at the underwater site of Piedras de la Barbada. Fishermen had captured two large masses of metal and marine concretions that turned out to be stacked helmets, fused together by corrosion materials, sediment and marine debris. They were thought to be Roman because the site is rich with Roman material, including amphorae, anchors and Punic War-era bronze helmets.The two concreted block were conserved and archaeologists counted at least 43 helmets in the two assemblages. (The figure comes from the helmets that can be counted on the surface of the two groups. There are probably more encased in the center of the blocks.) Two of them were separated from the blocks and placed on display at the Museo de la Ciudad de Benicarl. The original blocks and fragments that came off of them are kept in the Museu de Belles Arts de Castell.Researchers from the University of Alicante at first attempted to place them in a more narrow period by typological analysis, but there are traits from both Late Roman helmets and from later medieval helmets that were inspired by Roman design, and ultimately the team could find no direct parallels. It was radiocarbon dating of textile fragments found inside five of the helmets that conclusively determined their medieval origins.The dating revealed that these helmets were examples of a transitional style that was briefly trendy but that made no long-term on armor fashions.Specialists believe that all the pieces formed a single shipment when they hit the seabed. The most probable hypothesis is that the batch was packed and transported by sea when an incident occurred during loading or unloading operations. The cache was found at a depth of just six metres, right next to an area used as a jetty.Dr Graells suggested that a portion of the cargo became trapped under the sand and could not be recovered at the time. This accidental mishap allowed the package to remain hidden for centuries, safely buried out of sight.The exceptional preservation of the helmets was achieved through the combined action of marine concretions and sediment. In some specimens, these deposits sealed the fabrics lining the interior, creating stable micro-environments that protected organic materials that would normally decay. These very textile fragments proved fundamental to reconstructing the history of the hoard.The researchers place the sinking during a particularly turbulent period for the western Mediterranean. The expansion of Islamic piracy along the Valencian coast during the mid-14th century, alongside the growing militarisation of the coastline, generated a high demand for defensive equipment. In this context, the cargo may have been destined for local militias, troops of the Kingdom of Valencia, or armed companies tasked with protecting the maritime frontier.The findings have been published in the journal Antiquity and can be read in its entirety here.