Frankfurt was, once implemented, the dream of the architects of the Modern Movement. It showed what could be achieved with control over development, industrialized construction and social housing. In comparison with only thirty dwellings by Le Corbusier at Pessac, at Frankfurt 15,000 were built. It is also consciously experimented with the block, making it disappear and be replaced by another type of urban form – from which we are only now with great difficulty managing to escape. The link between municipal urban policy and architecture reached here a degree rarely equalled in other German cities. This is why we have thought it important to spend some time on it.