The study, led by researchers at the University of Alicante (UA), reexamined 43 helmets discovered in 1990 at the underwater archaeological site of Piedras de la Barbada near Benicarló on Spain's eastern coast. The findings, published in the Cambridge University Press journal Antiquity, show that the helmets were manufactured between the late 14th and early 15th centuries, completely overturning their long-standing Roman classification.

The research was led by Manuel Frallicciardi, a doctoral student jointly supervised by the University of Alicante and the University of Salerno.

Largest Medieval Helmet Hoard in the Western Mediterranean

The discovery itself happened by accident. Local fishermen pulled up two large masses of metal that had become fused together through centuries of marine corrosion after snagging them in their nets. Inside the concreted blocks was an extraordinary cache of iron helmets.

Although archaeologists believe the original shipment may have contained even more pieces, the surviving collection of 43 helmets already represents the largest known hoard of medieval helmets ever found in the western Mediterranean.

According to Raimon Graells, a lecturer at the University of Alicante, co-director of Frallicciardi's doctoral project, and co-author of the study, the significance of the find extends well beyond the artifacts themselves.

"We are looking at direct evidence of large-scale arms trading. This discovery reveals a network of exchange and communication that was far more complex than previously thought," he said.

The findings point to active movement of military equipment between the coast of what is now the Valencia Region and major commercial centers in northern Italy, including Genoa, one of the era's most powerful trading hubs. Researchers say the size of the shipment indicates that weapons were being transported through well-established commercial systems linking different parts of the Mediterranean.

New Analysis Reveals a Medieval Origin

One of the study's most important advances was the use of an analytical method developed at the University of Alicante. While the technique has been used successfully in other archaeological investigations, it had never before been applied to medieval weapons of this type.

Combined with radiocarbon dating of fabric fragments preserved inside several helmets, the approach allowed researchers to establish a highly accurate age for the artifacts.

Frallicciardi explained that identifying the helmets initially proved difficult.

"At the beginning, it was difficult to place them in a specific era because they featured traits that recalled both Late Roman models and potential medieval pieces inspired by classical traditions," he said.

The results became even more surprising when researchers discovered that the helmets did not match any previously documented category.

"When I started the research, it was incredible to see that practically no known parallels existed," Frallicciardi said.

While searching for comparisons, he found a few similar helmet depictions in 14th-century English artwork, but no exact equivalents. Carbon-14 dating ultimately confirmed that the helmets belonged to a poorly documented design from a transitional period in military technology that left no direct descendants.

A Lost Shipment Preserved Under the Seafloor

Researchers believe all 43 helmets were originally part of a single cargo. The most likely explanation is that the shipment was being loaded or unloaded when an accident caused it to fall into the water.

The site lies only about six meters (20 feet) deep and is located beside an area that served as a jetty.

Graells suggested that part of the cargo may have become buried beneath the sand immediately after the accident, preventing recovery efforts at the time. As a result, the shipment remained hidden for centuries.

The helmets survived in exceptional condition thanks to a combination of sediment and mineral deposits that formed around them underwater. In several cases, these concretions sealed off the interior lining, preserving pieces of fabric that would normally have decayed long ago.

Those textile fragments ultimately became one of the most important sources of evidence in reconstructing the history and age of the collection.

Piracy, Warfare, and Demand for Weapons

The researchers believe the shipment sank during a particularly unstable period in Mediterranean history.

During the mid-14th century, Islamic piracy expanded along the Valencian coastline, while increasing militarization created growing demand for protective equipment and weapons. In that environment, the helmets may have been intended for local militias, forces serving the Kingdom of Valencia, or armed groups responsible for defending the region's maritime frontier.

Far from being Roman relics, the helmets now offer rare evidence of medieval trade, military logistics, and the movement of arms across one of the world's most important commercial regions.