The Darug people were the Aboriginal peoples to the area in 1788.

The area was originally explored by British settlers in 1789 and the nearby eminence to the west of the Hawkesbury River was known by them as 'Richmond Hill'. The name was given by Governor Phillip, in honour of Charles Lennox, the third Duke of Richmond who was Master General of Ordnance in the Pitt administration. The local area was the third area to have European settlement in Australia after Sydney and Parramatta. The first 22 European settlers came to the area in 1794. They came to farm a total of 12 hectares (30 acres) in what is now Pitt Town Bottoms. They needed good farming land to help overcome the desperate need for food in the new colony. By 1799 this region was producing about half the grain produced in the colony.

The Battle of Richmond Hill took place in May and June 1795 between the Darug people and the European settlers. It is perhaps the first time that the colonial authorities sent in the troopers and expressly stated their intent to 'destroy' the whole local Aboriginal population of an area.  (Wikipedia)