Born in Kent in England, Quentin attended  Charterhouse School and was a Captain in the British Army during World War II.  Quentin participated in the Allied Landings in Sicily and mainland Italy in 1943-45 and was mentioned in dispatches for his service. He carried a piece of shrapnel in his leg for the rest of his life. He rose to the rank of Brigadier in the Australian Army Reserve.

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After the war, his mother had inherited the impressive Camden Park House and its surrounding farmland. In 1947, Quentin moved with his parents and his wife Andalusia (nee Riley) to Australia and they became prominent members of the Camden community.  Quentin and Andalusia had three children, Mark, Anne and Clare. After the death of his parents, Quentin took up residence in Camden Park and in 1959, after his divorce, married his second wife Antonia (nee Blaxland), a descendant of the colonial pastoralist and explorer Gregory Blaxland.  At his mother’s request, Quentin changed his surname to Macarthur-Stanham to ensure that the historic name of Macarthur continued and remained associated with the house and property. He and Antonia had two surviving children - John (1960-) and Jane (1964-) who both grew up at Camden Park.

 

He balanced a business life with managing and conserving the historic estate.  In the early 1970's the broader Macarthur-Onslow family agricultural enterprise underwent upheaval. The broader part of the estate was sold,  but Quentin was determined Camden Park House and its surrounding land would not be handed over to developers. He can be credited with having saved an important part of Australia’s history through his determination to retain Camden Park House in family hands. He and his second wife Antonia supported many local organisations and often made the house and grounds of Camden Park available to charities and fund raising organisations.  They organised the now very popular annual Open Weekend which raises money to preserve one of Australia’s finest colonial homes.