The objective of this article is to examine the transition from atomistic to oligopolistic competition within the British grocery food retailing market. The focus of the article is the period from the end of post-war rationing in 1954 to the passing of the Trading Stamps Act in 1964. It was during this decade that a multiple retailers fundamentally altered the nature of competition within the industry. This article maintains that it was this decade that also defined the future pattern of development of firms within the grocery retailing market. However, as the article makes clear, multiple retailers were neither united in their approach, nor entirely voluntary participants in this transformation.