Chemical and isotopic analyses confirm dietary change marks the Early Medieval Slavic expansion into Central and Eastern Europe

During the first millennium AD, the much-discussed Migration Period marked a major episode of demographic and consequent economic, social and political change across large areas of Europe. Slavic migration from Eastern into Central Europe, between 500 and 700 AD, brings a proposed change in ‘kitchen culture’ and subsistence, displacing Germanic (e.g. Longobard) groups elsewhere, marking the end of the Late Antique period and the beginning of the Middle Ages. Notably, organic residue analysis of a total of 75 vessels from across the span of these periods confirms a distinct dietary shift between these purported groups. Food can often be one of the most distinctive expressions of social, religious, cultural or ethnic groups and, here, we demonstrate that a clear reliance on millet, in the form of porridge made with milk and, possibly, honey or soups and stews with meat, dominates, likely brought from the Slavic homelands. Thus, absent in the late Antique period, a new diet based on millet may thus have been a contributing factor to the population increase during the Early Medieval period and the subsequent expansion by Slavic groups across Europe. Analysis of a large series of legacy radiocarbon dates from human and animal bone, supported by compound-specific lipid dating of four of the same vessels allows us to identify the turning point of the change in habitus, with Slavic-speaking communities with a new housing culture, foodways and burial rites appearing in Moravia (Czech Republic) and Lower Austria, by the latest 598 AD (but probably much earlier, between 560 and 590 AD). • Multidisciplinary study combining organic residue, compound-specific radiocarbon analyses and Bayesian modelling. • Identification of a proposed subsistence shift between Late Antique and Early Medieval period in Central Europe. • Pottery lipids reveal a new milk and millet diet (millet porridge) adopted by the emerging Slavic population. • Lipid dating combined with legacy dates confirm the “milk and millet eaters” appeared in Central Europe, by the latest 598 AD.