In the time of the Caliph Omar, the maneuvers of conquest were carried out on three wide main fronts, these being Iraq/Iran, Syria and Egypt. The two superpowers of that age were the Sassanid Empire, controlling the Iraq/ Iran region, and the Byzantine Empire, the provinces of which included Syria and Egypt. As the main factor accelerating and facilitating the conquests, we see the widespread presence of the military garrisons, which ranged from temporary to permanent. In these garrison towns, salaried soldiers and their families were housed by the Caliph. Every garrison was founded in a strategic location so as to provide the greatest military effect. In this study, we discuss these garrison towns, in particular those which were originally founded purely for military purposes, but later developed a civil structure, such as Basra, Kufe and Fustat