The recently concluded ‘People of the British Isles’ project (hereafter PoBI) combined large-scale, local DNA sampling with innovative data analysis to generate a survey of the genetic structure of Britain in unprecedented detail; the results were presented by Leslie and colleagues in 2015. Comparing clusters of genetic variation within Britain with DNA samples from Continental Europe, the study elucidated past immigration events via the identification and dating of historic admixture episodes (the interbreeding of two or more different population groups). Among its results, the study found “no clear genetic evidence of the Danish Viking occupation and control of a large part of England, either in separate UK clusters in that region, or in estimated ancestry profiles”, therefore positing “a relatively limited input of DNA from the Danish Vikings”, with ‘Danish Vikings’ defined in the study, and thus in this article, as peoples migrating from Denmark to eastern England in the late ninth and early tenth centuries (Leslie et al.2015: 313). Here, we consider the details of certain assumptions that were made in the study, and offer an alternative interpretation to the above conclusion. We also comment on the substantial archaeological and linguistic evidence for a large-scale Danish Viking presence in England.