As described in historical dictionaries

Patronymica Britannica (1860)

SAINT LIS. The originator of this family in England was Simon de St. Lis, a participator in the Norman Conquest. William is said to have offered him in marriage to his niece Judith, widow of Waltheof, a great Saxon earl, whom he had deposed and beheaded. The ladj' refused him ' because he halted in one leg,' and so he courted and won her elder daughter Maud ! He was afterwards raised to the Earldoms of Huntingdon and Northampton. See the whole story in Dugdale's Baronage. The ordinary corruption of the name is Senlis or Seulez.

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.


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