Following its domestication in the Fertile Crescent, barley spreads into the west of the Mediterranean basin during the Neolithic period and represents today a major cereal in many agrarian systems. Geometric morphometrics, a series of quantitative approaches for studying the size and shape variation of objects, has provided encouraging results for studying barley seed diversity. In that vein, the first aim of this study was to document the current barley morphometric diversity using 2950 modern barley seeds belonging to 64 varieties. We demonstrate that barley grains record morphological diversity of the ear (2-row/6-row, naked/hulled), winter and spring varieties and environmental factors during its cultivation. Using these results, the second aim was to document barley diversity at the archaeological site of the Gallo-Roman port of Lattara (Lattes, France) dated from the Iron Age to the Middle-Ages as an example of morphometric perspectives in archaeology. The large sampling carried out at the site allowed to analyse of 2000 archaeological seeds from 40 samples. Morphometric diversity from various sectors of the city and various periods (500 BC – 900 AD) can thus be contrasted and characterized in comparison to our modern reference collection. Its opens interesting perspectives for studying barley diversity over the eight millennia since the onset of agriculture in the whole of the northwest Mediterranean basin in the framework of the DEMETER project (ERC Starting Grant; PI A. Evin).