Amir al-umara

The office of amir al-umara (Arabic: أمير الأمراء, romanized: amīr al-umarāʾ), variously rendered in English as emir of emirs, prince of princes, chief emir, and commander of commanders, was a senior military position in the 10th-century Abbasid Caliphate, whose holders in the decade after 936 came to supersede the civilian bureaucracy under the vizier and become effective regents, relegating the Abbasid caliphs to a purely ceremonial role. The office then formed the basis for the Buyid control over the Abbasid caliphs and over Iraq until the mid-11th century.

The title continued in use by Muslim states in the Middle East, but was mostly restricted to senior military leaders. It was also used in Norman Sicily for a few of the king's chief ministers.