A genetic study has now reconstructed the maternal ancestry of Iron Age Iberians in north-eastern Spain, revealing a population deeply embedded in local continuity but influenced by long-distance female movements. The research, conducted by Daniel R. Cuesta-Aguirre, Cristina Santos, of the Universitat Autònoma de Barcelona, and their colleagues, is published in the Journal of Archaeological Science.

Reconstruction of an Iberian warrior’s cremation scene. Credit: Museo de Prehistoria de Valencia; CC BY-SA 2.0

The Iberian culture flourished from the 8th to the 3rd centuries BCE along the Mediterranean coast, where the Ilergetes, Cessetani, Indigetes, and Ausetani thrived through agriculture, metallurgy, and trade. Though they shared cultural features, the Iberians were far from uniform. Their common funerary practice—cremation—made genetic analysis impossible until researchers turned to an unlikely source: newborns.

As the adults were cremated, infants were often buried beneath house floors. The researchers examined 31 newborn remains from archaeological sites in Catalonia and were able to obtain mitochondrial DNA (mtDNA) from 21 of them. They added these data to 41 previously published profiles, making up the largest genetic dataset for Iron Age Iberians.

Mitochondrial DNA, inherited only from mothers, allows researchers to trace maternal lineages. The results revealed extreme diversity in every tribe, dominated by haplogroups H, J, K, HV0, and U—lineages already present since the Bronze Age. This implies that the transition to the Iron Age was gradual, with no large-scale population replacement.

Reconstruction of the Iberian city of Ullastret. Credit: Patrimoni, Generalitat de Catalunya; CC BY-SA 2.0

High mtDNA diversity is compatible with a patrilocal society in which women moved to their husbands’ communities. Such short-distance female movement maintained maternal lineages in mixed form and prevented sharp genetic separation among tribes. Though there were minor fluctuations in certain haplogroups, no trace of sharp genetic breaks was observed.

However, some maternal lineages showed long-distance mobility. One woman in Sant Miquel d’Olèrdola carried the North African haplogroup M1b, introduced most likely through Punic or Carthaginian contact. Another carried N1a1a1a3, which can be traced to the Near East, and the haplogroup K1a12a in Font de la Canya points to links with Anatolian or Phoenician trade.

At El Camp de les Lloses, belonging to the Ausetani tribe, there were rare haplogroups H33c and U4d2 that suggested Central European and Italian connections. Roman influence was present at the site, yet most women there appear to have been local. Nonetheless, Ullastret, a mᴀssive Indigetes settlement, exhibited an almost entirely local maternal profile despite its strong Mediterranean connections.

The study reveals a society deeply rooted in its own ancestry but subtly shaped by women’s migrations tied to trade and cultural exchange. The evidence highlights the interplay between local continuity and external influence in shaping the genetic landscape of Iron Age Iberia.

More information: Cuesta-Aguirre, D. R., Campoy-Caballero, M. R., Sandoval-Ávila, C., Busquets i Costa, C., Fàbregas i Espadaler, M., Sinner, A. G., … Santos, C. (2025). Mitochondrial DNA diversity in northeast Iberians during the Iron Age. Journal of Archaeological Science, 183(106390), 106390. doi:10.1016/j.jas.2025.106390