[1] In 1899 Badley and Powell (the latter borrowing heavily from his father, the Vicar of Bisham) purchased a country estate near Steep and constructed a purpose-built school, including state-of-the-art electric lighting, which opened in 1900.

The site has been extensively developed over the past century, including the relocation of a number of historic vernacular timber frame barns.

and L'Education nouvelle popularised the school on the Continent, leading to a cosmopolitan intake of Russian and other European children in the 1920s.

Under a programme of expansion and modernisation in the 1960s and 1970s under the headmastership of Tim Slack, the senior school grew from 240 pupils in 1966 to 340, thereafter increasing to some 465.

As well as playing fields, orchards, woodland, pasture, multiple sport pitches and a nature reserve, the campus also has two Grade I listed arts and crafts buildings designed by Ernest Gimson, the Lupton Hall (1911), which was co-designed, built and largely financed by ex-pupil Geoffrey Lupton, and the Memorial Library (1921).