Ancient grape seeds discovered at archaeological sites in Spain and Sardinia have offered new clues about the beginnings of wine production in the Iberian Peninsula, according to a study published in the journal Current Biology. Researchers, led by Carolina Royo from Spain’s Instituto de Ciencias de la Vid y del Vino, examined 28 waterlogged grape seeds found at seven different locations. These seeds date back more than 2,000 years, covering periods from the Iron Age to the Middle Ages. The study found that the oldest cultivated grape seeds from southern Spain date to about 1000 BCE. These seeds contain genetic markers similar to modern grape varieties found in the eastern Mediterranean and the Balkans. This evidence supports the theory that Phoenician traders, known for their extensive maritime networks, introduced domesticated grapevines to the region from the east. Further analysis showed that these imported vines interbred with local wild grape species. Some of the Iron Age seeds contained a mix of genetic traits from both wild Iberian grapes and domesticated varieties from the east. By around 2,500 years ago, a unique genetic group of Iberian wine grapes had formed, which is still present in the region today. One of the medieval grape seeds found in Valencia matched a modern Spanish grape variety known as Pasa Valenciana. This discovery highlights the long history of agricultural continuity in the western Mediterranean. Some of today’s Spanish and Portuguese wines are still made from grape varieties that carry genetic traits inherited from those early imported vines and their hybridization with local wild grapes.