In 1845 the school was forced to close as a result of a financial scandal. Following an Order in Council of Queen Victoria in 1880, which superseded the previous Royal Charter, the school was rebuilt on a different site in Camberwell, opening in 1883. It again catered to the need for schooling of boys in Camberwell, which by this time had grown considerably from its rustic origins. Its working population largely consisted of men working in the professions, clerks, journalists, tradesmen and labourers. Naturally, a grammar school provided an asset to the neighbourhood, with the prospect for boys to go on to University education.
In 1961, using the assets from the Greencoat School, a mixed elementary church school which had closed (having shrunk to a non-viable size during the second World War), a new science block was opened opposite the main school site in Wilson Road and named the Greencoat Building.
The 1883 building continued to be used until 1975, when the school moved south to Wallington. This was motivated by growing dissatisfaction with the school's buildings (the Great Hall could only accommodate half the school) and the plans of the Inner London Education Authority to force all grammar schools to become comprehensive. Fortunately, the growing London Borough of Sutton, which continued to operate the 11+, wished to introduce another grammar school and provided an ideal opportunity for the school to relocate. The original 1975 building in Wallington was phase I of what was intended to be a larger school built in three phases, but the original plans for the second and third phases were never put into practice. Instead there have been various additions made when funding has allowed: the Mary Datchelor wing for Music, the Art and DT block, the Sixth Form Centre, Foundation Building and Junior School.
The school was one of the first to be designated a specialist college in Mathematics and Computing in 2002. This status was re-awarded in 2007 along with a second specialism in the Arts.
The school acquired its officially sanctioned Coat of Arms