forts and cities of the coast, peopled and fortified them, and rebuilt those of them that were in need of being rebuilt. The same thing he did with the frontier cities. When al-Mahdi became caliph, he carried the work in the remaining cities and forts to completion and strengthened the garrisons. Muʿâwiyah ibn-ʿAmr states, "What we saw of the efforts of Hârûn the 'Commander of the Believers' in conducting invasions, and of his penetrating insight in carrying on the holy war was really great. The industries he established were not established heretofore. He distributed possessions in the frontier and coast cities. He brought distress on the Greeks and humiliated them." Caliph al-Mutawakkil ordered in the year 247 that ships be stationed on all the seacoast and that garrisons be posted on it.