A Royal Charter founded the School in 1829 as the junior department of the newly established King’s College of the University of London. Based in the Strand, the School was an immediate success. Many early pupils became eminent in public affairs, the arts and sciences and for much of the nineteenth century it was the School’s financial strength which sustained the College.

Needing space to expand, the School moved to Wimbledon in 1897 and was separated constitutionally from the College by a 1905 Act, which created the present Governing Body. The Junior School was established as a separate school in 1912.