This article reflects on aspects of the ecclesiastical landscape in southern Byzacena and western Tripolitania. The aim is to highlight the conditions of creation and the process of evolution of the ecclesiastical landscape in a territory with a particular geographical identity. In this context, the approach is based on three clearly defined conditions: first, the factors favourable to the appearance and then the development of Christianity in this space; secondly that its main episcopal seats were divided into three essential sets –the bishoprics of the ecclesiastical district called by late sources Arzugitana,the seats of the Gafsa region, and those of the coastal plains of Aradh and Jfara; finally, the particularities of the ecclesiastical landscape with its imprecise boundaries between ecclesiastical and administrative subdivisions and the low representation of Tripolitania in African councils and religious tolerance.