Thomas, the eldest son and most well known, might have been born around 1367 judging from the dates he entered the military; it has been suggested, primarily by Russell Kraus, that he was the son of John of Gaunt, whom he served under and received favours from; however, as stated previously, this parentage is unlikely. CriticsA strong relationship with Philippa has been suggested due to an assumption that Thomas chose to bear her coat of arms over Chaucer's. However, in the Special Collections of the Harvard Library is a deed with the name and seal of Thomas Chaucer using the arms of his father Geoffrey and there is no known example of Thomas Chaucer ever using a seal with the arms of his mother. Confusion over this has likely come about because the tomb of him and his wife, constructed by their daughter, Alice Chaucer, Duchess of Suffolk, uses Roet rather than Chaucer arms.