The earliest grant in the area was to Phillip Schaeffer who settled in 1791. The district comprising modern day Rydalmere, Ermington and Dundas was initially called "The Ponds" because of such natural features occurring above Subiaco Creek. Shortly after Schaeffer's, further grants were given to several emancipists, eight marines and two crew of HMS Sirius, on the northern bank of the Parramatta River at Rydalmere and Ermington. By about 1800 "The Ponds" became known as "Field of Mars". Presumably because of Mars being the god of war, and the military men that received land grants there. The parish of Field of Mars spread more or less from Parramatta to West Ryde and up to Carlingford and Eastwood. Later on to the north of this area along the Lane Cove river, a Field of Mars Common of 5000 acres was established. Today's Field of Mars reserve and cemetery are remnants of this common. Rydalmere was named by Thomas O'Neill when he purchased much of the 600 acres of Hannibal Macarthur's old Vineyard Estate, after it was put up for sale through the trustees by the Catholic church in 1877. Despite the myth surrounding O’Neill coming from England’s Cumbrian Lake District, he was born in Tipperary, Ireland in 1830, and accompanied his parents to Australia as a young lad, where he finished his education. He left for the Californian goldfields in 1849 and returned in 1851, the venture being quite profitable for him. He entered business with much energy and a strong drive which along with sound commercial instincts allowed him to retire a very wealthy man in 1877. Another myth is that O'Neill purchased the Vineyard estate as a speculator in order to quickly sell it and make a healthy profit. The facts don't tend to support this view. After the purchase, he established his "Fairmount Estate" which covered a considerable portion of Rydalmere, the boundaries more or less extending from Park Road (formerly Wharf St) to Spurway Street, the southern boundary being the Parramatta river, and the northern boundary being Subiaco Creek (formerly Bishop’s Creek). It was an orchard and pasture property "Fairmount" the family home he built, was said to be a very beautiful residence, and splendid views were to be had from its tower. It has long since disappeared and was thought to have been located near Victoria Road and Gammel St. The property sales and sub-divisions only occurred slowly, and appear to be a result of either being required for the advancement of the suburb, or the estate being divided over time by roads being established i.e. Victoria Road in 1886, rather than being sold off for a profit. Thomas O'Neill died on 13 March 1890 at Fairmount aged 59. His funeral service was held in St Mary's Cathedral, and he was buried in Waverley cemetery. He was said to have been a most amiable man, held in high regard by all that knew him. His was deeply involved in not only Irish and Catholic affairs, but public affairs in general. His charity spanned many years with his support of St Vincent's Hospital, The Good Samaritan Refuge and The Benevolent Asylum being on-going. His purse was never closed to charity. His final act before his illness was to donate the land and money to help the establishment of the Catholic church and school at Rydalmere. He still owned most of his Rydalmere property at the time of his death. Fairmount was later sold by the family and remained an orchard with a few building lots sold. It was not until after WW11, when the Housing Commission acquired it for public housing, that it was fully developed. So why did he name his property Rydalmere, a lake he probably had never seen? Well, he had owned an estate named Rydalmere, which he had sold years before buying the Vineyard estate and must have liked the name which he reused. Exactly where his first Rydalmere property was located is not known. Rydalmere is a lake in The English Lake District which gains its name from the nearby village of Rydal. Mere is an Old English word meaning "lake", or "body of water".

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