In 698, the Arabs conquered Carthage under Hassan ibn al-Nu'man and completed the conquest of the eastern Barbary coast. Anticipating attempts at Byzantine reconquest however, they decided to destroy it. The walls were torn down, the agricultural land ravaged, the aqueducts and harbors made unusable. They established their base instead at Tunis which was heavily expanded, though Kairouan remained the governor's capital until late-9th century.