ALLEN. From the personal name Alan, common in Isrman times. Edw. Allen or Alleyne, when he founded Dulwich College, 1019, directed that the master and the warden of his establishment should bear the name of Alleyne or Allen, a regulation which has always been adhered to without much inconvenience, on account of the numerousness of the families bearing it. There are more than fifty coats -armorial assigned to the surname.

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