Al-Musta'in
... that Al-Musta'in was the only Cairo-based Abbasid caliph to hold both political and spiritual power?
... that <b id="mwDPY"><a href="./Al-Musta'in_(Cairo)" id="mwDPc" rel="mw:WikiLink" title="Al-Musta'in (Cairo)">Al-Musta'in</a></b> was the only <a href="./Cairo" id="mwDPg" rel="mw:WikiLink" title="Cairo">Cairo</a>-based <a href="./Abbasid_Caliphate" id="mwDPk" rel="mw:WikiLink" title="Abbasid Caliphate">Abbasid</a> <a class="mw-redirect" href="./Caliph" id="mwDPo" rel="mw:WikiLink" title="Caliph">caliph</a> to hold both political and spiritual power?