by Mark Antony Lower, M.A., F.S.A. in his book 'The Worthies of Sussex' published in 1865
In 1797 Mr. Dallaway was appointed Secretary to the Earl-Marshal, an office which brought him into close connection with the College of Arms, and also led to his association with the county of Sussex. He resided principally at Arundel for some years, in that capacity. At the death of his patron in 1815, he was re-appointed to office by Lord Henry Howard, the deputy Earl-Marshal, and again subsequently when Henry Charles, Duke of Norfolk was, in 1824, enabled by Act of Parliament to execute the functions of his high office in person. In 1799, Duke Charles presented him to the rectory of South Stoke in this county, which he resigned in 1803, on his Grace's procuring for him the vicarage and sinecure rectory of Slynfold, which is in the patronage of the See of Chichester. In 1801 he exchanged for the rectory of Llanmaes in the county of Glamorgan, which had been given to him by the Marquis of Bute, the vicarage of Letherhed, in the gift of the Dean and Chapter of Rochester. The two benefices of Letherhed and Slynfold he held for the remainder of his life. In 1811 he obtained the prebend of Hova Ecclesia in Chichester cathedral, which in 1816 he exchanged for that of Ferring; the latter he resigned in 1826 to the Rev. Edmund Cartwright, on that gentleman's succeeding him in the Editorship of the History of Western Sussex.
In the meantime he had published several works Anecdotes of the Arts in England, Observations on English Architecture and Statuary and Sculpture among the Ancients. He also edited, in 1803, in five octavo volumes, The Letters and Works of Lady Mary Wortley Montague from her original manuscripts, with a memoir.
But it is to the History of Western Sussex that Mr. Dallaway owes his locus standi among our 'Worthies'. The literary and antiquarian world had long looked for the result of the zeal and ability displayed by Sir William Burrell in collecting everything illustrative of our county history; but first his ill health, and subsequently his death, disappointed such hopes, and the huge collections known as the Burrell Manuscripts lay a comparatively dead letter on the shelves of the British Museum. The Duke of Norfolk, participating in the common regret, munificently determined to publish at his own expense, under proper editorship, a selection of so much of those collections as should compose a history of the Western Division of Sussex. Upon this work, for due remuneration, Mr. Dallaway was employed; and the first volume, containing the preliminary history, and the topography of the City and Rape of Chichester, was published in 1815.
The history of county histories is for the most part a history of misfortune: in too many instances the authors have incurred ruinous loss: in others, by some apparent fatality, the copies have been burnt or otherwise destroyed. Of the five hundred impressions of Dallaway's Western Sussex, about 125 had been disposed of, when a fire at the establishment of Messrs. Bensley destroyed all the remainder. The fate of the first part of the second volume (the Rape of Arundel) was even still more unfortunate. At the time of the fire above-mentioned, sixty copies had been sent out to be stitched, and were thus saved: all the rest perished.
Mr. Dallaway's other works were, a description of the Vicar's Garden at Letherhed to accompany thirteen etchings by Mrs. Dallaway; William Wyrcestre Redivivus notices of church architecture in the fifteenth century; various contributions to the Archaeologia, the Retrospective Review, the Gentleman's Magazine, &c. In 1826 he superintended a finely embellished edition of Walpole's Anecdotes of Painting, which includes Vertue's Memoirs of the English Painters and Engravers. But however accomplished in his acquaintance with art, and refined in his taste, Mr. Dallaway may have been, it cannot be concealed that he was by no means calculated for either a biographical or a topographical historian; and both this work and his History of Sussex abound with marks of haste, carelessness, and inaccuracy. Such is the opinion of a friendly biographer, which, so far as the latter publication is concerned, I am compelled to adopt. The typography and the illustrations of the work are of the highest merit, but it abounds with errors so manifest that one can rarely accept a fact or a date without collateral evidence, or reference to the original sources of information.
Mr. Dallaway died at Letherhed June 6th. 1834, aged 71, and was buried in the church-yard there, beneath the luxuriant boughs of a widely-spreading elm, which attracts the admiration of every passenger.
 Gent. Mag., ut supra
 The Rev. Edmund Cartwright, upon whom devolved the completion of the History of Western Sussex, reprinted 250 copies of the Rape of Arundel in 1832.
 This accomplished lady, Harriet-Anne, daughter of John Jefferies, Esq., Alderman of Gloucester, is I believe still living (1864). In 1828 she published A Manual of Heraldry for Amateurs. By her Mr. Dallaway had an only child, Harriet-Jane.
 Gent. Mag., ut supra