[2] Caboonbah Homestead was built in 1889-90 for grazier Henry Plantagenet Somerset and his wife Katherine Rose (née McConnel) and their family.

[1] During the 1880s Somerset managed a New South Wales pastoral station and meatworks before returning to Queensland to purchase a property of his own.

In 1888 he secured approximately 20,000 acres (8,100 ha) in the Mount Stanley area of the Brisbane Valley as a grazing farm, intending to erect his family home there.

He engaged a brickmaker to start making bricks for the chimneys, and employed men to pit-saw pine logs brought down from the ranges.

The property, mostly comprising rich alluvial flats, was divided into 7 paddocks and was devoted to fattening bullocks, dairying and horse-breeding.

The brickmaker employed at Mount Stanley made 30,000 bricks at the head of Sapphire Gully, to the west of the house, and erected a service building containing a bakery, washhouse and storerooms.

[1] Henry Somerset sustained heavy financial losses, estimated at £11,000, during the 1893 floods and was obliged to sell his Mount Stanley holdings to secure the family homestead at Caboonbah against debt.

[1] From 1904 to 1920 Henry Somerset served as the Member of the Legislative Assembly for Stanley, being returned 6 times by his electorate.

Eminent American engineer Allan Hazen also inspected the site and agreed that it had potential for future development, but recommended that a dam on Cabbage Tree Creek would solve Brisbane's more immediate needs.

Lake Manchester, on Cabbage Tree Creek, was completed in 1916, putting the Stanley River proposal on hold.

Caboonbah was resumed in 1973 by the Queensland Government as part of the Wivenhoe Dam project, and was leased for 10 years by Mr Carseldine's brother Max until 1983, when the Brisbane Valley Historical Society obtained an occupation permit.

The property was transferred later to the Brisbane and Area Water Board, which removed all but one of the original timber outbuildings associated with the homestead.

[1] The original plan was a central corridor with four main rooms, an attached service wing and verandahs to the north, east and south.

Internally the homestead retained many of the original fittings, including cedar surrounds to the fireplaces and a coved timber ceiling in the dining room.

The floor was concrete, the walls were of hand-made brick with some minor timber frame divisions, and it had a corrugated galvanised iron roof.

The place is also closely associated with local social and political events, in particular representing the legislative power of the Queensland Government in the Stanley electorate from 1904 to 1920.

The design, with its wide, low verandahs onto which every room opens, high ceilings, opening fanlights above French doors, roof ventilator and low timber stumps, illustrates the adaptation of traditional British architectural taste to Queensland climatic conditions.

A lack of refurbishment in a more pretentious style to accompany the increasing status of its owners reflects the aesthetic and cultural values of our nation builders.

[1] The place has a special association with the life or work of a particular person, group or organisation of importance in Queensland's history.