Theo Nicholson (David Theodore Field Nicholson) was born in 1894 in Waverley, Sydney.
His father was James Beath Nicholson and his mother was Ethel Catherine Beath.
His father James had migrated from Scotland in 1885 and had helped to established and later owned the Standard-Waygood Company which was a large engineering firm.
Theo went to work in his father's engineering business and later took over the management of the company.

In 1920 Theo married Elinor Young (Winifred Elinor Broughton Young) who was born in 1896 in Bundaberg, Queensland.
Her father was Horace Edward Broughton Young and her mother was Ellen Elizabeth Thorne.
The Young family owned a property called Fairymead Sugar Plantation near Bundaberg.
Elinor met Theo when her family came to Sydney for holidays to escape the heat.
Both the Nicholson and Young families were very religious and were strongly involved in Christianity.
During the 1930s the Nicholson family conducted a Sunday School at The Hermitage.
This was a lively household with family, servants and frequent visitors, all interacting under the careful guidance of Elinor Nicholson.
The house had not been the scene of such vivacity since the Blaxland family had occupied it.

In 1923 Theo and Elinor bought The Hermitage and lived there until 1952.
Five of their six children were born there.
One of their daughters Elinor Catherine (Dr Catherine Hamlin AC) became famous for her work in obstetrics and gynaecology to women in Ethiopia.
She has written a book about her life in which she gives some colourful details of her childhood at The Hermitage.
She wrote:
When I was a child the house seemed huge with endless rooms and a big attic in which we could crawl about and play with all the old junk that had accumulated over the years.
There were eight bedrooms.
The upstairs attic rooms were rather poky, but my father had gable windows put in and then we had a beautiful view all the way down to the Parramatta River.
Downstairs the rooms were wood panelled and there were wide verandahs in the front and back of the house.
The garden was my mother’s special interest and delight.
It was beautiful and, to me the most perfect garden I have ever been in..
— Dr Catherine Hamlin AC, 2001.
The Hospital by the River: a Story of Hope.

Her brother Peter Nicholson also gave an account of his childhood at the house called “The Hermitage: Memories of the 1930s.
He said that the property had orchards and vegetable gardens and that the family kept hens for eggs and had a cow that was milked.
In 1997 Peter Nicholson, the third of the family's children (born 1926), recorded an account of his life there as a child and young adult.
A copy of this is held by Ryde City Council.
He recollected from his childhood in the 1920s and 1930s that the house was surrounded by paddocks and plenty of ground, somewhat isolated from the rest of the community.
The family had orchards, grew its own vegetables, fowls, eggs, milk and that in those days tradespeople used to deliver goods.
The butcher, greengrocer, fishmonger would come once a week.
The baker would come.
The family kept a boat in a shed (Hoyles Boat Shed) in Drummoyne.
Mr Nicholson used to drive his car to work in the city, over roads so rough he would drive on the tram tracks to get a smooth ride.
Mrs Nicholson had a car also.

The children had a nursery - playroom, upstairs.
 The upstairs rooms were recalled as "originally very pokey little rooms" and Mr Nicholson had the windows across the front of the house put in and made them habitable and with good views.
A couple of the servants lived upstairs.
The front verandah was not used much as it faced south and was cold.
There were wooden columns covered with Ficus (probably dwarf creeping fig, Ficus pumila var.pumila.
Peter recalled that when the CSIRO first went to the Hermitage they pulled out the front verandahs wooden columns and made unattractive sandstone ones.
These have since been replaced with timber, and painted green.
The family used the rear verandah more, which faced north and was sunny.
The Nicholsons had the house's cedar j
Theo Nicholson (David Theodore Field Nicholson) was born in 1894 in Waverley, Sydney. His father was James Beath Nicholson and his mother was Ethel Catherine Beath. His father James had migrated from Scotland in 1885 and had helped to established and later owned the Standard-Waygood Company which was a large engineering firm. Theo went to work in his father's engineering business and later took over the management of the company.
In 1920 Theo married Elinor Young (Winifred Elinor Broughton Young) who was born in 1896 in Bundaberg, Queensland. Her father was Horace Edward Broughton Young and her mother was Ellen Elizabeth Thorne. The Young family owned a property called Fairymead Sugar Plantation near Bundaberg. Elinor met Theo when her family came to Sydney for holidays to escape the heat. Both the Nicholson and Young families were very religious and were strongly involved in Christianity. During the 1930s the Nicholson family conducted a Sunday School at The Hermitage. This was a lively household with family, servants and frequent visitors, all interacting under the careful guidance of Elinor Nicholson. The house had not been the scene of such vivacity since the Blaxland family had occupied it.
In 1923 Theo and Elinor bought The Hermitage and lived there until 1952. Five of their six children were born there. One of their daughters Elinor Catherine (Dr Catherine Hamlin AC) became famous for her work in obstetrics and gynaecology to women in Ethiopia. She has written a book about her life in which she gives some colourful details of her childhood at The Hermitage. She wrote:
When I was a child the house seemed huge with endless rooms and a big attic in which we could crawl about and play with all the old junk that had accumulated over the years. There were eight bedrooms. The upstairs attic rooms were rather poky, but my father had gable windows put in and then we had a beautiful view all the way down to the Parramatta River. Downstairs the rooms were wood panelled and there were wide verandahs in the front and back of the house. The garden was my mother’s special interest and delight. It was beautiful and, to me the most perfect garden I have ever been in..
— Dr Catherine Hamlin AC, 2001. The Hospital by the River: a Story of Hope.
Her brother Peter Nicholson also gave an account of his childhood at the house called “The Hermitage: Memories of the 1930s. He said that the property had orchards and vegetable gardens and that the family kept hens for eggs and had a cow that was milked. In 1997 Peter Nicholson, the third of the family's children (born 1926), recorded an account of his life there as a child and young adult. A copy of this is held by Ryde City Council. He recollected from his childhood in the 1920s and 1930s that the house was surrounded by paddocks and plenty of ground, somewhat isolated from the rest of the community. The family had orchards, grew its own vegetables, fowls, eggs, milk and that in those days tradespeople used to deliver goods. The butcher, greengrocer, fishmonger would come once a week. The baker would come. The family kept a boat in a shed (Hoyles Boat Shed) in Drummoyne. Mr Nicholson used to drive his car to work in the city, over roads so rough he would drive on the tram tracks to get a smooth ride. Mrs Nicholson had a car also.
The children had a nursery - playroom, upstairs.  The upstairs rooms were recalled as "originally very pokey little rooms" and Mr Nicholson had the windows across the front of the house put in and made them habitable and with good views. A couple of the servants lived upstairs. The front verandah was not used much as it faced south and was cold. There were wooden columns covered with Ficus (probably dwarf creeping fig, Ficus pumila var.pumila. Peter recalled that when the CSIRO first went to the Hermitage they pulled out the front verandahs wooden columns and made unattractive sandstone ones. These have since been replaced with timber, and painted green. The family used the rear verandah more, which faced north and was sunny. The Nicholsons had the house's cedar j
The Hermitage, Denistone