At that time the area was open forest, but after New South Head Road was built in 1831 timber cutters felled most of the trees, and the land was subdivided.

Around the middle of the 1800s residents included the Reverend George Fairfowl Macarthur, one time rector at St Mark's Church, Darling Point, members of the Tooth family, brewers, at Swifts, and Samuel Hordern, retail king.

[4][1] By 1841, a portion of Jones & Potts' land and of Smith's grant (making up 4.5 hectares (11 acres)) was purchased by Thomas Woolley, ironmonger, who built a two-storey stone cottage "Percyville" on the site with John Frederick Hilly as architect.

A cottage originally occupied the site, and the owner, Thomas Sutcliffe Mort, built the sandstone Gothic Revival mansion around this building, circa 1850–1860.

The interior was based on the Palace of Westminster and is considered to be an outstanding example of Blacket's work,[6][7] with stained-glass windows, tiled floors, an elaborate staircase and panelled library.

The position of a label mould indicates an early stair in that area but its date and origin are unclear), stained glass windows to the stairhall and old study (G14 and G13), and an extension to the south (G5, G4B).

[4][1] Mort, businessman and horticulturist, was born in Bolton, England and worked as a clerk, seizing the chance to migrate to Sydney in 1838 to bolster the family fortunes.

His pastoral interests included Franklyn Vale, in the Darling Downs, Queensland and Bodalla at the mouth of the Tuross River, South Coast, NSW.

Mort pioneered weekly wool auctions and the refrigeration of food, was involved in moves for the first railway in NSW, and was a founder of the AMP Society.

Mort used architect F. J. Hilly who transformed the original cottage Percyville (which stood in more than 2.8 hectares (7 acres) of ground) into a two storied Gothic Revival gentleman's residence.

[9][10][1] Mort enjoyed his wealth and it gave rein to a natural flamboyance which, often hidden in his personal dealings, was epitomized in his house where it flowered in Academic Gothic Revival extravagances.

Among other acquisitions were Elizabethan armour, old English coats of mail, a cabinet that had belonged to Marie Antoinette, antique oak furniture and about 120 pictures.

On his return he engaged architect Edmund Blacket to make additions to the house (including a covered carriageway, stables and kitchens[8]) and an art gallery which, with his gardens, were open to the public.

[1] At meetings of the Australasian Botanic and Horticultural Society in Sydney Mort first met newly arrived Irish-English nurseryman and landscape designer Michael Guilfoyle.

Greatly impressed with his knowledge and experience and having heard something of the prowess of the Guilfoyle family in England in such matters, he commissioned him to develop and landscape Greenoaks.

As noted above, Mort was president of the Horticultural Society of NSW, publisher of the magazine, and Guilfoyle was listed in it as one of the "good and first rate gardeners" formerly employed at Greenoaks.

[1] Mort owned land down the hill from Greenoaks, in Double Bay, where he had his vegetable garden, and offices and Guilfoyle occupied a cottage there (at the corner of South and Ocean Streets).

In this nursery Guilfoyle stocked flowering and evergreen trees and a wide selection of conifers, "probably one of the most complete in the colony" (journal entry by exteemed visiting English nurseryman John Gould Veitch in 1864).

He is known to have sought two cases of Norfolk Island pine (Araucaria heterophylla) from Charles Moore in 1855, (which may have been the source of the specimen depicted in an 1857 engraving of Greenoaks).

[15][1] In 1860 Mort acquired the Bodalla estate on the South Coast of NSW, where his gardener Michael Bell took up farm management, replaced at Greenoaks by George Mortimore.

The Governor's unveiling of the statue was witnessed by hundreds of workers who had voluntarily forfeited a day's pay in order that they might be present for this final tribute to their late employer.

The subdivision and sale was at auction on the proviso: "Any building erected on the land must be of brick or stone with roof of slates, tiles or shingles and most cost and be of a value of not less than A£750".

[1] Between 1911 and 1913 renovations were undertaken for the church by architect, J. Burcham Clamp, replacing shingle roof with slates, installing electricity, new water and sewer servies, fixing and supplying outside Venetian blinds, fences to boundary lines, entrance gates, stone steps to the lawn, erection of a tennis screen, repairs to the tank over the main laundry, erection of a summer house on the western boundary, converting the small chapel into a library, removing the kitchen (basement to ground floor level), erecting balconies, probably over the northern verandah, removed in 1927), partial subdivision of the picture gallery, construction of a small bathroom extension (G1), replacing some window sashes, general repairs – some internal rearrangement of the Blacket wing, new window to the library.

[19] Further alterations and additions were made in 1959 by R. Lindsay Little: work on the drainage system, retaining walls, redecoration of the interior (including removal of some original decorative elements in the drawing room and stair hall), a new hot water system, alterations to cloak room and toilet facilities and removal of outdoor fencing.

[27][1] The sale returns to private hands one of the great heritage estates of the eastern suburbs, comparable to the nearby, much larger Swifts mansion which was formerly home to the Catholic Archbishop before it was bought by the Moran family.

Former archbishop Peter Jensen vacated it when he retired in July 2013, and it was formally listed to expressions of interest two months later; however, his successor Glenn Davies moved back in during 2014 after the property originally failed to sell.

Wang debuted on the Forbes Rich List of China in 2014 as a result of his early investment in the Beijing Zinwei Telecom Technology Group.

It is a very fine domestic Gothic house built 1850s around an already existing cottage considerably enlarged by Hilly, Blacket and others, and features:[1] The coat of arms of the Mort family are carved on the sandstone walls.

Thomas Sutcliffe Mort pioneered weekly wool auctions and the refrigeration of food, was involved in moves for the first railway in NSW and was also one of the founders of the AMP Society.

[1] The then 4.5-hectare (11-acre) estate and part of the mansion also have associations with Thomas Woolley, a Sydney ironmonger, who built a two-storey stone cottage "Percyville" on the site with J. F. Hilly as architect.