The Ribat of Sousse is the oldest and best example of the ribat style of buildings that spread in North Africa during the Middle Ages. A series of small fortifications known as "ribs" were built along the north African coast during the ninth and tenth centuries to accommodate military and religious functions. The Ribat of Sousse was built At the end of the eighth century, its architectural style is generally inspired by the style of the Byzantines who preceded the Arab invaders on African lands, and in fact, building materials dating back to antiquity were widely used in the construction of this historical monument.