Post-War educational policies were radical, but not radical enough for London's social educational agenda. The London County Council, the largest education authority in England, pursued a revolutionary type of education that led to a completely new type of secondary school, despite the urgent need to repair considerable war damage. The launching of the new comprehensive school was a daring operation involving the controversial closing of numerous established schools. Their policy was divisive, generating opposition from politicians of both sides, from the government and even within the council. This thesis charts the history of the architecture of the London comprehensive school. It is a critical review comparing London with national developments, and examines the way the new educational requirements led to a new architecture for the new comprehensives. Architects were at last able to practise modernist architecture for a social purpose, and design for increased complexity in architecture and function. The authority's architects, together with numerous private practices, were able to creatively design schools with a great diversity of modernist architecture. The architecture and how it was perceived together with educational planning is examined. The early difficulties faced in launching the new schools and the special problems of the city school are highlighted. System construction and the reasons why it was not relevant for London are also discussed. This is the first time a wide-ranging selection of London schools has been collated, examined and evaluated. It reveals a rich collection of English modernist architectural developments. The London urban school, ranging from the fifties with Kidbrooke school, to the eighties and into the age of High-Tech with Waterfield, is recorded. Comprehensive schools are now being radically reinvented, altered or demolished, and this work attempts to record the making of their architecture before the history is lost.