Themes

Mavi Boncuk The multilateral internal turmoil in the Byzantine empire during the 7th and 8th centuries brought about administrative changes and led to the establishment of the system of themes.

The term '-thema-' (theme) originally meant the list of soldiers in a local corps. Later it was identified with the army corps itself, and finally it was associated with the place where the specific military unit was posted. In other words the theme was a military, administrative and geographical entity headed by a 'strategos' (general). The 'strategos' was appointed by the Emperor and exercised supreme military and political authority in the region of his jurisdiction. Each theme was divided into smaller administrative districts, and its troops were mainly recruited from the local peasantry.

The first themes must have been created in the provinces of the East in the 2nd half of the 7th century, in order to deal more effectively with the various problems of defence there, since under the new system the 'strategos' in charge was invested with both military and political power.
By the 9th century the system of themes had been extended to the rest of the Empire, in an endeavour by the emperors to weaken the all-powerful governors of the earlier dioceses. However, the uniting of the two authorities in the person of one 'strategos' once again created all-powerful local lords who posed a threat to the central authority. From the second half of the 11th century the emperors tried to face this danger through the separation of political from military authority and the continuous fragmentation of the large themes into smaller administrative districts ('katepanikia').

The 'strategoi' became simple commanders of army divisions and the term "theme" now denoted only geographical regions or small fiscal departments. After the capture of Constantinople by the Crusaders (1204) the theme organization collapsed.