Al-Andalus was divided into cora or provinces, each of which had a capital governed by a wali. Each cora was split into districts, which played a part in the taxation and administration of the area. The marches, or borderlands, were under the command of military governor. The northern march, around the Ebre River and which included the districts of Larida and Turtusha, was administered from Saraqusta. Numerous husun (castles and forts) were built along the border. Balagha became an important defensive place on the frontier, where Hispanic families, such as the Banu-Qasi, and Arab families, such as the Banu Hud, acquired considerable influence.