I originally wrote a rather detailed history of the families behind this property, but found that it rambled a little bit. Let me give you the potted version, then.

1823: Anthony Hordern (1788-1869), a free immigrant from the north of England and member of a banking family, arrived in Sydney. He established a retail store.

1856: His son, also named Anthony (1819 -1876) because some families need to be told that you don't REALLY have to reuse the same names every generation, also set up a retail business in Sydney (though he had also been involved in earlier ones with the family).
He brought his son named (I can't believe this) Anthony (1842-1886) into the business. Later he brought his younger son who finally had a name of his own, Samuel (1849-1909) into the business and renamed it Anthony Hordern and Sons, which became an institution in Sydney for about a century.

1886: By now Anthony the 3rd had become a railway entrepreneur in Western Australia. He died while returning to Australia by ship from London. That left Samuel as the sole proprietor of the Anthony Hordern's business since their father had died 10 years earlier.

1887: Although Samuel was very prosperous, the alleged "upper classes" always looked down on people who were "in trade"; that is people who actually work for a living. How do you get around that? You buy land. You build grand houses. You breed livestock, as long as you don't get your hands dirty while doing it. You breed thoroughbred horses. In this way you become "landed gentry". And thus, Samuel obtained a large area of land in the Southern Highlands outside of Bowral, built a grand, ornate, Italianate mansion on it, and bred stock. This is it. It was called Retford Park after the family's former Sydney residence Retford Hall, which was in turn named after the town in Nottinghamshire where the very first Anthony Hordern's wife came from.

The house passed through the hands of the 2nd Samuel Hordern (oh my loving gods; (1876-1956)) and his younger brother Anthony (don't say it, though at least this one went by the name of Tony, 1889-1970). Samuel II had a son called... Samuel (1909-1960), who was killed in a car accident near Liverpool in Sydney.

After his death, the property briefly passed through the hands of an American pastoral company which wanted the lands rather than the house.

1964: James Fairfax, heir to the Fairfax newspaper empire, heard about the house and decided to buy it and some of the land around it to turn it into a gentleman's retreat. James became head of the newspaper company following his father Sir Warwick Fairfax's retirement in 1977.

1987: James' half-brother launched a disastrous takeover bid to re-privatise the company, and James Fairfax sold out and left the business. The half-brother was also named Warwick Fairfax (facepalm) though he was commonly referred to as "young Warwick" which I don't think anybody ever used as a term of endearment. The company was driven into receivership (remember the 1987 stock market crash? Great timing!), and after riding out its receivership was re-floated as a public company. In the meantime James retired to his sumptuous property to serve on company boards, raise livestock, collect art, engage in philanthropy, and generally live a pretty grand life as the squire of his country mansion.

2017: That life ended at the age of 83. As far as I can determine he had never married and had no children so he bequeathed the property and some of the land to the nation via the National Trust. Some of the land was sold off to help fund maintenance of the property, and the remainder of the costs are met by tours such as the one we did this day.

It's a most interesting property in many ways, and you could spend hours exploring the gardens if you had the time. If you get the opportunity to visit Retford House, I do encourage you to take it. (Ideally on a clear, blue, sunny day, the likes of which we haven't had for about a month.)