He was early attracted to the study of antiquities by the rich stores of ancient documents preserved in the muniment room of his patron at Stow Hall.
In February 1843 he exhibited to the Society of Antiquaries of London from that collection a book of the swan marks of the River Ouse, from the time of Queen Elizabeth I.
He had then nearly completed at his private press a small volume (in a limited edition of only 36 copies) entitled Vice-Comites Norfolciae, or Sheriffs of Norfolk from the first year of Henry the Second to the fourth of Queen Victoria.
[3] In 1859 he exhibited to the Society, also from Stow Bardolph, a roll entitled Magnus Annulus, a sort of calendar extending from 1286 to 1817, and containing genealogical notices of the Hare family.
A much more important work on which he was engaged, with his friend, Joseph Jackson Howard, LL.D., was the earliest heraldic visitation of Norfolk, 1563, accompanied by a supplement of illustrative documents, and with many of the pedigrees brought down to modern times.
William Blythe, Lynn, 1863, was enriched with a series of Fincham pedigrees which were actually put in type by Dashwood, and printed at his private press.