In 1371 a Carthusian monastery was founded on what is now the north side of Charterhouse Square. This was dissolved in 1537 and in the following years was used variously as a mansion house, a hospital and a school. By 1894, the area had started to fall into decline and the often-vandalised square was commonly used for illicit purposes.

As the decline in this middle-class area continued, most of the private homes disappeared. The remaining residences on the eastern side were demolished in 1935. This cleared space for the development of Florin Court, originally named the Charterhouse Hotel, which was built in the style moderne between 1936 and 1937.

Arranged over nine floors, the internal layout and size of the apartments in Florin Court was dictated by an expectation that early starting workers at nearby Smithfield Market would find the flats convenient pieds-à-terre. The London County Council granted a special variance allowing the centre of the façade to be recessed, the only design compromise being that the uppermost floors in the projecting wings be set back. The unusual façade allowed the top floor flats to have small roof gardens and provided a view of the square below to the greatest number of rooms. The ground floor originally included a porter's office and flat for the head porter, with a public restaurant, cocktail bar and club in the basement.