The market for insurance has become increasingly competitive in recent years. However, it has not always been so. At the end of the nineteenth century, it was characterized by a highly concentrated and tightly controlled oligopolistic market structure. As such, the history of the fire insurance industry provides an interesting case study in the development of collusive behaviour amongst firms. Up to 1897, pricing agreements among firms were generally short-lived, and were followed by periods of intense competition. After this point, an agreement was forged, which proved very resilient to market pressures and formed the basis of premium rate setting until the 1970s. This paper investigates the difference between this agreement and previous efforts to set premium rates, and points to some of the common features of the later compact, which explain its longevity.