While famed for her marriages to Italian prince Marco Torlonia and Australia's first equestrian Olympic gold medallist Laurie Morgan, it is perhaps Ms Torlonia's relationship with her late cousin and art dealer Frank McDonald that makes this sale all the more exciting.

The Clune Galleries co-owner was described as more of a brother to Ms Torlonia and hanging on the walls at Hardwicke are rare works by Australian colonial artists Charles Conder and Alfred James Daplyn.

Daplyn's 1898 oil painting, The Australian Artist's Dream of Europe, is expected to sell for more than $30,000 at the public auction at Hardwicke Stud on Sunday, March 22.

An Olympic games jacket, tailcoats and saddles that belonged to the late Laurie Morgan are also up for sale, along with a hitching post presented to 1884 Melbourne Cup winner Malua and Martin Stainforth paintings of the horse Trafalgar, believed to be trained or sired at Hardwicke.

Clothing modelled by Ms Torlonia for Chanel including a Frederick Starke black velvet cape and Prue Acton coat are also among the collection, as well as convict items and a late 19^th century rosewood later ebonised Bluthner grand piano.

"In your life as an auctioneer, you probably come up against these sorts of sales once every two years where everything has been held intact by the same family for that many generations with a fantastic international flavour," managing director of auction house Lawsons, Martin Farrah, said.

Just to walk through Hardwicke is something to marvel at, in particular the bird foyer dedicated to ornithology, and all of this is open to the public to see on Saturday, March 21, Lawsons director for on-site sales Shauna Farren-Price said.

"It's quite reflective of these very old, well-established, financially stable rural families who live in these grand homes," Mr Farrah said.

While some of Ms Torlonia's items are expected to fetch thousands of dollars, there are also many everyday, affordable items for sale including furniture, white goods, china, old maps and prints, and jewellery.

Ms Torlonia nee McDonald grew up in Australia in the horse country of Scone. She bought Hardwicke from the father of the notorious Freedman brothers horse trainers Tony Freedman.

Despite holding onto Hardwicke, Rome has been her home for many years and will continue to be, Mr Farrah said.

"It gets to a stage where the property needs up-keep and furniture needs to be polished, silver needs to be cleaned... It becomes too much for people," he said.

Hardwicke Stud was well-renowned for breeding horses for many years until it was forced to give them away due to the drought.

The stud made it into the news in October 2019 when an ABC investigation into the slaughter of racehorses found horses from Hardwicke ended up at a Queensland abattoir.

A representative of the Yass Stud told Canberra Times they denied sending their horses there.

The Hardwicke homestead and adjoining stables recently sold and Lawsons has been instructed by Ms Torlonia to auction the contents.

Members of her family in Australia are expected to attend the auction.

"We certainly enjoy a good live sale and I think they're really looking forward to the festivity of it," Ms Farren-Price said.

The viewing will be from 10am-4pm on Saturday, March 21 and the auction will be from 11am on Sunday, March 22.