Note 1169 — Chapter XII · STONE CASTLES OF THE NORMAN PERIOD

The earliest instance of a portcullis groove with which the writer is acquainted is in the basement entrance of Colchester. It is obvious to anyone who carefully examines this entrance and the great stair to the left of it that they are additions of a later time than William’s work. The details seem to point to Henry I.’s reign. The keep of Rochester has also a portcullis groove which seems to be a later addition.