Geographic distribution of sites and temporal distribution of individuals 4000 BCE-43 CE. Newly reported in black; published in orange. Base maps made with Natural Earth; elevation data Copernicus, European Digital Elevation Model v1.1. The Britain map labels sites harbouring ancestry outliers relative to others of the same period. The timeline shows archaeological periods in the British chronology: Neolithic (3950–2450 BCE), Chalcolithic and Early Bronze Age (C/EBA, 2450–1550 BCE), Middle Bronze Age (MBA, 1550–1150 BCE), Late Bronze Age (LBA, 1150–750 BCE), and pre-Roman Iron Age (IA, 750 BCE-43 CE). We add jitter on the Y axis and sample dates from their probability distributions (Supplementary Table 1).