Aboriginal people from the Cabrogal tribe, a sub-group of the Gandangara tribe, have lived in the Fairfield area for over 30 000 years. European settlement began in Fairfield in the early 19th century. Horsley Park was originally part of Colonel George Johnston's 2,000-acre (8.1 km2) property "Kings Gift", which was given to him by Governor King for his part in putting down the Irish Rebellion at Vinegar Hill in 1804.

After his death it passed to his daughter Blanche who in 1829 married Major George Nicholas Weston. He built an Indian colonial style homestead on the property and named it "Horsley" after his birthplace in Surrey, England. Horsley Homestead is one of the few remaining early colonial buildings in the Fairfield district today protected by The Australian Heritage National Trust.  (Wikipedia)