Margaritus of Brindisi, called "the new Neptune", was the last great ammiratus ammiratorum of the Kingdom of Sicily. Following in the footsteps of Christodulus, George of Antioch, and Maio of Bari, Margaritus commanded the kingdom's fleets during the reigns of William II (1166–1189) and Tancred (1189–1194). He probably began as a Greek pirate and gradually rose to the rank of privateer before becoming a permanent admiral of the navy. In 1185, he became the first count palatine of Cephalonia and Zakynthos. In 1192, he became the first Count of Malta. He also held the titles of Prince of Taranto and Duke of Durazzo.

The office of amir al-umara, 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.