Database: A Difficult Succession
At the death of a caliph, another one succeeded him immediately. But sometimes, deciding who that other would be was a complicated and dangerous task.
The Abbasid empire possessed clear rules about succession. Any male member of the ruling family could in theory become caliph, as long as he commanded the support of enough key elements of the government. After the passing of a ruler, a power struggle could therefore ensue between the various candidates and their partisans in the army or the administration. The harem, where the caliph's family and children lived and where he usually spent his last days, was another important factor in these scrambles.
The reigning caliph usually tried to nominate his successor. He could choose any of his male relatives but often favored one of his sons, if he had any. He then attempted to ensure that his chosen candidate would receive the support he needed by shoring up his position in the army and by having key members of the government and the Abbasid family take religious oaths to respect his decision. He would sometimes include the name of this chosen heir on coins struck by him. When the caliph had been a respected and powerful figure, these measures would usually suffice. But if not, or if his chosen successor was a divisive figure—a child, one of many brothers—nothing prevented the soldiers and the administrators from trying to push for another candidate. After the reign of al-Mutawakkil (r. 847-861), caliphal succession became more heavily contested than it had been in the early days of the dynasty, and it often led to coup attempts and sometimes civil war.
A coin issued during the reign of al-Muhtadi (r. 869-870) shows that successions did not always go according to plan. In addition to al-Muhtadi's name, this coin includes traces of the names of the previous caliph, al-Mu'tazz (r. 866-869), and the name of his son and then apparent heir, 'Abd Allah', who never became caliph.