(….) a small Vinkings (or Scandinavian) population conquered parts of modern France, and then adopted the local form Old French, giving rise to ‘Norman’ French. This, in turn, was then imported into England, and greatly affected the development of English, although not to the extent of being completely adopted. Perhaps ironically, the Germanic speech of the residents of England was thus altered by the (Romance, not Germanic) linguistic practice of the invaders, whose biological relation to the English was in many cases somewhat closer than the linguistic one.
Anderson, Stepehn R, Languages, a very short introduction, OUP, 2012 (p25)