Although he appears to have been inactive in the Regency art market we know that John Theophilus Daubuz was a distinguished book-collector. He was listed among the subscribers to John Rutter’s de luxe Delineations of Fonthill and Its Abbey (London: Charles Knight & Co., etc., 1823) and was remembered as recently as 1908 in William Carew Hazlitt’s Roll of Honour: A Calendar of the Names of Over 17,000 Men and Women Who Throughout the British Isles and in Our Early Colonies Have Collected Mss. and Printed Books from the XIVth to the XIXth Century (London: Barnard Quaritch, 1908, p. 57).
However, Mr. Daubuz is conspicuous for having consigned to an auction sale at Christie’s in Pall Mall, on March 30, 1805, a group of “Italian Pictures, of the very distinguished class, recently consigned from Italy,” more specifically, it seems, acquired indirectly and rather mysteriously from the Palazzo Barberini in Rome (lots 6–38). At this date Prince Carlo Barberini-Colonna, Prince of Palestrina and Duke of Montelibretti (1735–1819), was inclined to seize any opportunity to sell anything to anyone, but Mr. Daubuz probably got this stash of paintings through an intermediary, almost certainly in Paris, during the brief period following the Peace of Amiens when Britain and France were not at war (1802–03). Travel from England to the continent before and after this brief spell was impossible, and, during it, travel beyond Paris was more or less practically so.
Despite this spectacular provenance, and the wildly ambitious attributions of almost every picture, all but a very few were left unsold. It may well be that the London trade conspired to lock out this newcomer to the art market, and punish him.
According to the Getty Provenance Index, it seems likely that after this debacle Mr. Daubuz either off-loaded his Barberini pictures somewhere on the continent, or else put them in the attic or a box room at Leyton. A few may well have passed with the rest of his chattels to Brother Charles.
In any case, Mr. Daubuz’s lots at that sale purported to include (1) a portrait of Abramo Federici by Francesco Apollodoro; (2) a Madonna and child by Federico Barocci; (3) an italianate landscape by Jan Both; (3) a Madonna and child by Guido Cagnacci (£31 10s); (4) and (5) a St. John the Evangelist and a companion St. Matthew by Simone Cantarini (Simone da Pesaro); (6) a wooded landscape by Claude; (7) and (8) “a pair of pleasing landscapes and figures” by Adriaen van Diest (£6 15s); (9) a St. Jerome by Carlo Dolci; (10) a portrait of “an abbess” by Sir Anthony van Dyck; (11) a portrait of a woman by Lavinia Fontana; (12) and (13) two portraits, a man and a woman by Giorgione; (14) a landscape with cattle by Johannes Glauber (£6 6s); (15) an estuarine landscape by Jan van Goyen (£8); (16) (17) (18) and (19) a St. Joseph and a companion Madonna, an infant St. John the Baptist, and a St. Anthony of Padua—all by Guercino; (20) a portrait by Bartholomaeus van der Helst, and the pièce de résistance, (21) Salome, the Daughter of Herodias, with the Head of St. John the Baptist, by Leonardo da Vinci. None of these painting may now be indentified with any degree of certainty.
The date of Mr. Daubuz’s unfortunate, possibly damaging entrée to Christie’s coincides almost exactly with his purchase of “The Great House” at Leyton. According to the Reverend John Kennedy:
This house was built by Sir Fisher Tench, Bart., who lived in it till he died—October 31st, 1736, aged 63. The Rev. John Strype describes it thus:—“Of more modern erection are the Magnificent and beautiful seat & habitation of the late Sir Fisher Tench, Bart., adorned with large and most delightful gardens, plantations, walks, groves, mounts, summerhouses & pleasant canals stored with fish and fowl, and curious vistoes & prospect, which upon the death of Sir Nathaniel Tench, son of Sir Fisher, came to his sister Jane Tench, who married Mr. Sowerby; and his children have very lately sold it to Mr. John Stanniland of London, Harberdasher; as also the fair & pleasant tho’ lowly situated Manor House of Leyton.”This passage was neatly plagiarized a few years later by the author of a privately circulated pamphlet, with carefully barbed embellishments, as follows:
This house originally had two wings, from one of which the cupola now on the tower of the parish Church was taken. The present front of the house was originally the back; the present High Road and the County Cricket Ground being fields attached thereto. The High Road then followed nearly the line of the present Scott’s Road, the estate on that side extending as far as the Philli-Brook, which divided it from the Phillibrook estate.
In 175o it was purchased by Thomas Oliver, Esq., a West Indian Merchant, and Alderman of London…In 18o5 John Theophilus Daubuz bought the Great House Estate from the heirs of Alderman Oliver for £5,8oo. Mr. Daubuz was of French extraction, his ancestors having come to this country at the time of the Revocation of the Edict of Nantes…Mr. Daubuz died in 1831 [sic], leaving his estate to his elder daughter [sic], Ann Hand Mary Daubuz, with the exception of the present Grove House, and two fields adjoining it, which he left to his younger sister, Magdalen Daubuz. Ann Hand Mary Daubuz died in 1836, leaving her estate to her married brother, Lewis Charles Daubuz, of Truro; he lived with his daughter at the Great House till he died in 1839. His two sons, Charles Lewis and William, now inherited it, and by them it was let first in 184o to Stephen Cattley, a Russian Merchant, who with his family lived in it till about 1845, when it was let to Mr. Kennard, and after him it was let as a school to Mr. Arnold, a relative of Dr. Arnold, of Rugby. In 1855 it was a boarding house, under the management of Mr. Dovey. From 1858 to 186o it was inhabited by James Daubuz, the eldest son of Lewis Charles Daubuz; soon after this date it was rented by Mrs. Davey (then Woods), and a few years after she purchased it; and now it is used by her as a private lunatic asylum. (A History of the Parish of Leyton, Essex, Leyton: Phelp Brothers, High Road, 1894, pp. 327–329.)
John Theophilus Daubuz bought the house and lands from the heirs of Thomas Oliver for £5,800, and it is probable that about this date  the extensive alterations carried out in the style of the Brothers Adam, were made. Mr. Daubuz was of French extraction, his ancestors having come to this country at the time of the Revocation of the Edict of Nantes (1685). Apparently something of a Philistine he (among other alterations) converted the two fine panelled rooms for use as domestic offices, had much of the panelling in other rooms stripped from the walls, which were canvassed and papered, and the remainder of the woodwork including the staircase and hall, painted stone colour! He is also credited in the Parish Records with blocking church improvements which threatened encroachment on his family pew…[Soon after 1860] the house now became a Private Lunatic Asylum (a fate which has helped to preserve many a fine mansion in districts which have seen better days) and as such it continued to be used until 1896. After remaining in the market for some time it has now been acquired by Mr. Miles and seems likely to share the fate of the Manor House, Leyton Grange, and other fine houses destroyed long since to furnish accommodation for the housing of the ever-increasing population of London. Should a purchaser be found there is a chance of reprieve, as although the greater part of the extensive grounds are already built over, having in fact furnished space for the formation of several new roads, the house still stands and is offered for sale as a club or institution, for which purpose it is well adapted. It is to be hoped that it may yet be spared—Greater London can ill afford to lose such relics of times that are past. (The Great House, Leyton, by Edward Gunn, Architect. Being the Fourth Monograph of the Committee for the Survey of the Memorials of Greater London, London: E. Arnold, S. Buckley, 1903, pp. 15–16.)Like many other landowners, in 1830 Mr. Daubuz was directly affected at Leyton by the so-called Swing Riots. Several of his haystacks at Leyton were set on fire. The following notice duly appeared in the London Gazette:
Whitehall, January 25, 1831. Whereas a reward of one thousand pounds was offered in the London Gazette, of the 21st of December last, to be paid by John Theophilus Daubuz…to any person giving such information as should cause the apprehension and conviction of the person or persons who, on the night of the 14th of the said month of December, set fire to a stack or stacks on the premises of the said John Theophilus Daubuz, at Low Leyton, in the county of Essex; and whereas no information hath been obtained tending to the discovery of such offenders; notice is hereby given, that the said John Theophilus Daubuz hath withdrawn, and doth hereby withdraw, the aforesaid offer of reward, and that the same will not be paid after the date hereof. (No. 18772, February 1, 1831, p. 196.)Since Leyton eventually passed from John Theophilus Daubuz to Lewis Charles Daubuz, and thence to the elder brothers of John Claude Daubuz, sometime Rector of Creed in the Diocese of Truro, it is impossible to know whether many of the chattels found their way to Cornwall. It seems likely that the replica of Gainsborough’s The Cottage Door came into Mr. Daubuz’s possession by that route, because this is the only even remotely plausible context in which he came to own it.
In 1836, John Theophilus Daubuz was listed as a Justice for the Peace in the County of Essex.