Euphemius or Euphemios was a Byzantine commander in Sicily, who rebelled against the imperial governor in 826 AD, and invited the Aghlabids to aid him, thus beginning the Muslim conquest of Sicily.

The Aghlabids were an Arab dynasty centered in Ifriqiya from 800 to 909 that conquered parts of Sicily, Southern Italy, and possibly Sardinia, nominally as vassals of the Abbasid Caliphate. The Aghlabids were from the Najdi tribe of Banu Tamim and adhered to the Mu'tazilite rationalist doctrine within Hanafi Sunni Islam, which they imposed as the state doctrine of Ifriqiya. They ruled until 909 when they were conquered by the new power of the Fatimids.