caliph
The supreme religious and political authority of Muslims, considered successor of Muhammad (Arabic: khalifa = deputy). He was the head of the Caliphate, the religious state of the Arabs.

domestikos ton scholon
Commander of the regiment of scholae. The first officer with this title appears in 767/8. In the 10th C the domesticos became very powerful among the army of the themata; in mid-10th C the office was divided in two, domestikoi ton scholon of the East and those of the West, commanders in chief of the eastern and the western provinces´ army respectively.

doukas (lat. dux)
Antiquity: Roman military commander who, in some provinces, combined military and civil functions.Buzantium: a higher military officer. From the second half of the 10th c. the title indicates the military comander of a larger district. After the 12th c., doukes were called the governors of small themes.

emir
(from Arabic amir) Emir meaning "commander" or "general", later also "prince". Also a high title of nobility or office in some Turkic historical states.

enkyklios education
The secondary education in Byzantium. The students, from 12 years old, were taught grammar, rhetorics and eloquence.

protomandator
The senior officer of the corps of messengers (mandatores), at the service of Byzantine military commanders and of the Byzantine Emperors.

strategos ("general")
During the Roman period his duties were mainly political. Οffice of the Byzantine state´s provincial administration. At first the title was given to the military and political administrator of the themes, namely of the big geographic and administrative unities of the Byzantine empire. Gradually the title lost its power and, already in the 11th century, strategoi were turned to simple commanders of military units, responsible for the defence of a region.