Fortresses such as those at Marvão would now deter any spring offensives against the Banu Marwan from the Emirate in Córdoba. These offensives by the Emirate were common against another rebellious Muwalladi, notably those against Umar Ibn Hafsun, based in Bobastro near Ronda. However, the relative peace and endurance of the Banu Marwan's statelet - 46 years - testifies to the impregnability of its castles: any Emirate offensive in the São Mamede would be a bloodbath.