Aghlabids
The Aghlabids were an Arab dynasty of emirs from the Najdi tribe of Banu Tamim , who ruled Ifriqiya and parts of Southern Italy , nominally on behalf of the Abbasid Caliph , for about a century , until overthrown by the new power of the Fatimids . 
<triplet> Aghlabids <subj> Fatimids <obj> replaced by <triplet> Caliph <subj> Abbasid <obj> has part <triplet> Fatimids <subj> Aghlabids <obj> replaces <subj> Abbasid <obj> replaces <subj> Caliph <obj> instance of