'Nailed-head ritual' in Iron Age Spain was more 'complex than initially thought'

Traditionally, it was believed that severed heads, sometimes pierced with iron nails, were displayed as war trophies to intimidate enemies. However, a study published on March 13, 2025, in the Journal of Archaeological Science: Reports suggests that the ritual's meaning varied across different settlements, reflecting complex social dynamics.

The research team analyzed seven severed male skulls from two Iron Age sites: Puig Castellar in Barcelona and Ullastret in Girona. By examining stable strontium and oxygen isotopes in the dental enamel of these skulls, the researchers determined the geographic origins of the individuals. At Puig Castellar, three out of four skulls exhibited isotopic signatures differing significantly from the local baseline, indicating they were likely non-local. In contrast, Ullastret displayed a mix of local and non-local origins among the skulls.

An example of a 'nailed head' from the Iron Age site of Ullastret in Spain.
Credit: © MAC-Ullastret a De Prado, 2015

These findings suggest that at Puig Castellar, the display of severed heads may have served as a symbol of power and intimidation, particularly targeting outsiders. Conversely, at Ullastret, the ritual could have been a form of veneration for esteemed community members, regardless of their origin. The placement of the skulls further supports this interpretation: at Puig Castellar, skulls were found near exterior walls, possibly to deter external threats, while at Ullastret, skulls were located within the settlement, potentially honoring local individuals.

This study underscores the importance of integrating bioarchaeological and isotopic analyses to gain a deeper understanding of ancient cultural practices. It challenges previous assumptions about the uniformity of the nailed-head ritual, highlighting the diverse ways Iron Age communities in northeastern Spain utilized this practice to express social and political dynamics. Further research is necessary to fully comprehend the ritual's role across different settlements and its impact on the social structures of the time.