They became umarā (emirs) with defined duties and responsibilities, and spheres of influence became known as emirates.
1994, Gehad Auda, “The ‘Normalization’ of the Islamic Movement in Egypt from the 1970s to the Early 1990s” in Accounting for Fundamentalisms: The Dynamic Character of Movements (The Fundamentalism Project, volume IV), eds. Martin Emil Marty and R. Scott Appleby (paperback edition, 2004), →ISBN, part III, chapter xv, §: ‘The Nature and Limits of the Sunni Revolution’, sub-§: «Organizational Dynamics», sub-sub-§: ‹The Muslim Brotherhood›, 381:
In the classical Ikhwanist structure, there are four types of membership: assistant member, affiliated member, working member, and mujahid, or combatant, member. In the Jamaʿa, however, there is only one type — the working membership. Whereas there is no title of amir (prince) in the Brotherhood structure, every university faculty has a jamaʿa which is headed by an amir. Umaraʾ (pl. of amir) of the faculties constitute the Shura Council of the university, which also has an amir at its head. Umaraʾ of the Egyptian universities constitute their Shura Council, headed by an amir chosen from among them.
1995, Ralph W. Brauer, Boundaries and Frontiers in Medieval Muslim Geography (Transactions of the American Philosophical Society, volume LXXXV, part vi), →ISBN, § 1: “The Geographical Concepts”, sub-§ 1.2: ‘Boundaries in the Arabo-Islamic Geographic and Historical Texts’, sub-sub-§ 1.2.1: «Internal Frontiers», 8:
From the death of Muhammad, the khalifs responded to the increasing size of their dominions by delegating authority to umaraʾ (pl. of amîr) who were in charge of the military campaigns as well as of religious affairs in the various provinces.
“How well you appreciate the historicity of the situation, perhaps alone among the contemporary umara. And how interesting to contemplate the parallel facing the present emir — your brother — and his and your great-great-great-uncle, Mustafa bin —”
