Abstract : The White-Williams-Greenberg diagram, also called the square of White, illustrates the repartition of health care as it was assessed in the sixties based on US and UK observations. The concept of the ecology of medical care led to passionate debates. The present article aims at reviewing the history of the square of White and of its successive adaptations. It will focus on its influence in various fields, such as research in primary care, general practice and teaching of medicine.