Rousham was built in 1635 by Sir Robert Dormer and the house is still owned by the same family. Colonel Robert Dormer-Cottrell inherited the property in 1719 and employed Charles Bridgeman to lay out the gardens.
The Stonor family have lived in the Park since the twelfth century with the earliest parts of the current house dating to the fourteenth century with later additions c1600. The house was part Gothicised by John Aitkin in the eighteenth century.
In 1927, Beatrix Havergal and Avice Sanders left Downe House to establish a gardening school. They took over the lease of Waterperry House and land from Magdalen College, Oxford in 1932.